Catherwood, J. - Queen's University Belfast

Tearing Down the Slippery Slope
John Catherwood, Lecturer in Applied Ethics
Address for Correspondence: School of Politics, International Studies and Philosophy, Queen's University
Belfast, 21 University Square, Belfast BT7 1PA, Northern Ireland. Email: j.catherwood@qub.ac.uk
The logic of ‘Slippery slope’ arguments and their related variants ‘the thin end of the wedge’
‘opening the floodgates’ ‘great oaks from little acorns’, etc., has been widely criticised. Yet
these ‘slope-type’ arguments remain popular in the messy business of real-life moral discourse
even at the highest levels of social policy making. [1] I believe that a hitherto unregarded
property of these arguments plays an import role: it is the imagery used that makes these
arguments attractive and persuasive and we need to analyse the image if we are to understand
the appeal of these arguments and successfully debunk them. J NI Ethics Forum 2006, 3: 42-51
Each image has particular properties which require exploration, but there are two aspects that
all slope-type arguments share: they appeal to caution and to cynicism. When faced with
novelty which may have dire moral implications people look on the new activity with caution
and perhaps fear. ‘Better safe than sorry’ is the maxim invoked; slope-type arguments sow the
seed of doubt. Caution and experience tell us to avoid any possibility of permitting evil. Even if
only one person became a heroin junkie after trying legalised cannabis, or one doctor slid
towards killing patients against their will, one is one too many.
These arguments also play on a cynical (if often justified) view of our fellow man. Descent to
the bottom of the slippery slope is inevitable: temptation, like the pull of gravity, is constant and
unavoidably drags us down. The claim that no abuse will follow from relaxing a strict moral
principle is always dubitable. We might have enough moral strength to avoid the moral decline
or horrible result that slope-type arguments predict, but we know that others are not so rational,
strong-willed or morally aware. These aspects of the arguments are especially pernicious
because most people have problems with the proper assessment of risk and probability. The
most miniscule risk can become a powerful influence if the possible outcome is emotionally
charged.
Although all slope-type arguments play on the emotional responses outlined above, the
different images that each invokes have their own peculiar emotional and psychological force.
The most powerful of these is the Slippery Slope itself.
No matter what is at the bottom of it, the prospect of facing a slippery slope is enough to raise
tension in even an experienced mountaineer. The image has an emotive effect that is drummed
into us from childhood: “Be careful that you don’t slip!” is every parent’s cry to adventurous
toddlers. Slipping leads to falling, to pain and embarrassment. Even if a fall is avoided, anyone
who has ever slipped unintentionally will know the discomfort of that experience. To slip is to
loose control and be in danger of harm. Of course we are not morally responsible for actions
over which we have no control, but we would be morally irresponsible to put ourselves
knowingly in a position where control will be lost and harm caused. It is not merely fear of
falling that the image evokes; it is fear of the possibility of falling.
The slippery slope image is also an attack on our self-image, as well as a threat to our personal
safety. We are in the centre of the picture. It is us who will slide to the moral low. Some forms
suggest we will become corrupt and no longer recognise our acts as evil. All imply that we will

e unable to rise again to the moral heights. It suggests that we are weak, corruptible, a notion
reinforced by the related image of our lives being ‘a moral journey’ on which we could become
‘lost’.
Negative associations are not the sole root of power for the Slippery slope image. Unlike the
images of floodgates and wedges, which are almost entirely fuelled by implied threats, the
Slippery Slope image also draws on flattery and self-delusion. People like to think of
themselves as good, and there is a flattering appeal in the suggestion that we are at the top of
a slope. It implies that we are better than those who are foolish or morally corrupt enough to
have hit the bottom. We are already on ‘the moral high ground’, a common positive image
which also implies the existence of a moral low ground, and presumably slopes to connect
them. It is in many people’s nature to take pleasure in looking down on those below.
However if we further unpack the slippery slope image it becomes incoherent. A slope (slippery
or not) is a three dimensional shape, which must be set in a ‘moral landscape’. This image is
supported by many others: the moral high ground, mountains to climb, paths to tread (some
broad and paved with good intentions, others straight and narrow), sloughs of despond, moral
mazes and bridges up ahead. These metaphors and analogies seem meaningful since for most
of us our primary sense is vision and it is natural for us to talk in spatial and visual terms even
when describing abstract, non-spatial things. So we talk of ‘moral positions’ as if they were
spatial positions and understand the notion of a person being close to our position, or of our
aims being higher than others. The image of sliding down the slope suggests that we are
capable of moral movement within the landscape and that we can become better or worse
people, make moral progress and perhaps climb ever higher through moral struggle. All of
these ideas are controversial.
While moral change is undeniable, progress is not. Progress implies goals and purpose and
improvement measured against standards. Individuals and societies change their opinions but
whether or not the changes are for the better is open to debate. ‘Progress’ will be defined in
terms of whatever moral principles we hold at the time, and any changes in our moral position
may also change our notion of what it is to progress. Some predictions of deleterious moral
change have come true, but we look upon those changes as progress, given our new moral
position. [2] Perhaps we are now corrupt, but equally we may have slipped upwards, or slipped
along so that we are now neither better nor worse. Perhaps we did not slide at all; we walked a
deliberately chosen path, applying a little moral grit when necessary.
It is also difficult to fully cash out the idea of moral movement. When we change our opinions it
is natural to use the imagery of having ‘shifted’ positions, or being ‘moved’ by an argument.
However there is no physical movement and there is no object that transfers from one place to
another in normal space time. If there is moral movement then it can only happen in moral
space, which itself needs further examination.
Whatever moral space is like, ‘moral movement’ is still mysterious, for there is no moral
corollary of Newton’s Laws of Motion. There is no mass to my thoughts to be accelerated in
law-like way by (moral?) force. We may talk of our thoughts having ‘momentum’, but we are not
doomed to continue to change our position at a constant rate unless stopped, nor to have an
equal and opposite reaction to moral forces brought to bear on us. Physical movement occurs
through space and over time – we move from one place to another by moving to adjacent
places in sequence until the final destination is reached. Moral ideas, even ideas about the
same or similar issues held by the same person at one or different times, do not require
contiguity, (they may be radically different or even reversed, and bear no relation to each
other). A change in moral position can be instantaneous without passing through a series of

other positions in moral space, even if the new position is far from the old. In a moment’s
thought I can be instantly at the bottom of the slope, without having to slide down it. Or I may
leap to the top, avoiding the slippery surface altogether.
We also have to consider how many positions in moral space one person can hold at any one
time. We speak of ‘having a position on this issue’, which suggests we could have other
positions on other issues. However to make sense of the image of an individual being located
in moral space it seems strange to think of them as having more than one position. Of course
there could be more than one moral space: I have a position in moral space related to drug
legalisation, a different space for abortion sees me in a different position, etc, but this is also
counter intuitive. If we are to be able to make anything coherent of this image of a slippery
slope lying before us on the path of life then we have to imagine one person on one path in one
landscape. The image requires that at any time we only have one position, representing a
summation of all our moral ideals and opinions.
In moral space many individuals may occupy the same position, like angels on the point of a
pin. What happens if all of these people take different decisions and move away from the
shared position, each deciding about a different issue, and each making their choice in the face
of claims that a slippery slope awaits them? The landscape now imagined must consist of
multiple slopes all centred on the high ground of the shared position. At the same time there
may be movements that can be made that do not lead on to a slippery slope, or which lead up
or merely along. So we must imagine a point in our landscape with a large (infinite?) number of
possible paths intersecting at all angles, on which potentially infinite numbers of individuals can
stand together. Now consider that every other point in the landscape is similarly surrounded by
a similar (infinite?) set of paths of every type and direction, since each point in moral space
represents a possible position from which one may move any distance in any direction if a new
decision is taken. We soon lose any comprehensible image of a single landscape, or the idea
of a path. Even if we reduce the image to its simplest, so that we stand on firm ground at the
top of a hill, we are still at a loss to make sense of what supports the surface upon which we
are supposed to step. What is the moral rock beneath our feet?
Perhaps the moral landscape could be seen as a snapshot of our current position and the
moral choices available to us. We could view the moral landscape as a model, or a map, of the
moral reality for each individual. This interpretation emphasises the personal nature of the
moral journey. However in this personalised landscape one position may simultaneously be at
the top of many supposed slopes (slippery or not) and at the bottom of many others, and
anywhere in between. Perhaps it is just a lack of imagination on my part, but I think that even
M.C. Escher would be unable to draw this image.
Moral space would have a different and confusing topography for each person, and since each
individual may change their ideas over time the map/landscape would change accordingly.
Such change could be rapid, extreme, and unpredictable. Moreover each individual may also
rearrange the scenery by altering which ideas they think are close to each other and which are
separated. We might be able to agree that some particular position is morally similar in many
respects and on the same level as another, but that does not mean that the two should be side
by side. There are no common frameworks to suggest how the landscape should be organised.
Indeed we could imagine a moral landscape that was made up of near random distributions of
heights and depths [3] with no visual similarity to any real world geography.

Organising principles might be developed if we knew what the x and y co-ordinates of each
point represented (height, the z axis is clearly moral worthiness). We can imagine a one
dimensional representation of a moral position easily enough – a simple line with ‘good’ at one
end and ‘evil’ at the other. We can place ourselves and others on this line, perhaps using a
summing technique to determine how good or evil we are over all. We could regard movement
towards good as moral progress. We could also extend this to two dimensions, perhaps plotting
our position over time, with goodness on one axis and time on the other. Here we can make
sense of the slope image if we see a downward plot as our goodness falls from a highpoint.
However the difficulty in climbing back up the slope is supposedly because it is slippery, and
there is some force akin to gravity that drives us down, not because it is impossible to travel
backwards in time. If we wish to keep the analogy with a conventional landscape which can be
traversed in any direction, then time must be the fourth dimension, and flows only one way.
There do not seem to be any good candidates for what the other two axes could represent.
Talk of a landscape without some understanding of the substrate of which it is built or the
dimensional system by which it can be measured or described is not just metaphorical, or even
allegorical. This image is not using language normally used to refer to one type of object or
experience to refer to a different, but in some way similar or related, object or experience. This
is not a simplifying analogy that informs and improves our understanding: we are not even
using the image in a symbolic way. Direction, position, movement and extension (along with
attributes of extended objects such as shape, texture or colour) are all impossible to
understand without the context of understandable dimensions. It sounds like meaningful
English, but on reflection it is no more meaningful than “Colourless green ideas sleep furiously”
Any terms (such as ‘slope’) that rely on an understanding of these things are meaningless. The
consequences for those who wish to use a Slippery Slope argument are plain: without a
comprehensible shared notion of a moral landscape then the whole notion of a moral slope,
slippery or otherwise, is misconceived. It obscures and misrepresents the issue we want to
discuss. Since such a notion is not comprehensible, and the landscape is not shared, the use
of a slippery slope argument is at best empty, at worst a flagrant attempt to influence by
deception and emotional manipulation.
The excuse that it is ‘just an image’, or even that it is a useful image, is not good enough. It is
useful only because it seems meaningful, and because it is manipulative. If it is just an image,
then why not use another image, one that is not manipulative or deceitful, one that is
meaningful, and does not carry the sense of quiet, waiting, inevitable menace that the slippery
slope suggests? Indeed it might be a useful test of any slippery slope argument to reword it as
a slope-type argument with a different image
Few acorns grow into mighty oaks. They are driven by forces of nature, and grow
independently of human desires, but the process is not inevitable, and can be interrupted. We
cut down or uproot even well established trees that are growing in the wrong place. It lacks the
menace of the slope image, which may be why it is not as popular in general discourse.
If we talk of ‘the thin end of the wedge’ we must also conjure the image of the wedge as being
something that has to be placed, and has to be driven. We may wonder who is the person
wielding the sledgehammer to drive the wedge home, and why are they doing it? Perhaps the
person driving the wedge can be questioned or stopped and their strength or determination
may fail. At least they are a human agent, morally responsible and culpable, not a morally
neutral or inevitable force of nature. This image at least gives us something that we can fight
against. We might also wonder what the wedge is being driven between, or into. In a culturally
diverse society such as ours it is not plausible to suggest that morality is a smooth and solid

ock, homogenous and offering no natural splits or faults. While wedge drivers might exploit
these splits, they ma be doing society a favour in exposing the weaknesses that are already
present.
Floodgates are a thing of which relatively few people in most modern urban cultures will have
much experience, and so it lacks the immediate and personal impact of the slippery slope. The
image of a flood also lacks the subtle notion of progression that the gentle but unstoppable and
ever accelerating slide down a slope suggests. It is implausible in many cases because it is
overly dramatic. If one stands before the floodgates one is soaked, swept away and maybe
drowned within moments of their opening: unless it is obvious that an immediate progression
will be made directly to ‘the horrible result’ this image is unconvincing. Again, a flood may pass
and gates can be closed, so this image is not one of inevitability or permanent change. It is also
notable that while a flood may leave terrible damage, the evil is an external one – those who
speak of floodgates may be warning us against foolhardy haste which might lead us into a
situation that we do not like but they are not suggesting that we will become irrevocably bad
people.
My favourite image to substitute is that of ‘letting the camel’s nose under the flap of the tent.’ It
lacks seriousness. No doubt it is a serious thing to have a camel in your tent, and for those
desert nomads who coined the ancient proverb it was a real danger, but in our modern lives it
lacks the emotional impact that the Slope argument can deliver. It is more likely to raise a smile
than to produce grave nods of agreement. It also has an old fashioned ring to it, sounding like
the sort of thing a retired military man who once served in the Raj might say in his club. We
would understand that this is the sort of person who would be typically a natural conservative
(perhaps not in tune with the times). If the argument still seems credible, despite the humour of
the image, I think it must be worth considering seriously, but any lasting credibility is to be
found in the unpacked version, not the clichéd image by itself. It is notable also that the camel’s
nose argument lacks the impersonal inevitability that sliding on a slippery slope suggests.
Camels are wilful and curious, and not known to be forward thinking or concerned for the
welfare of human beings: the same is not necessarily true of the principles, actions or actors
against whom the slope argument is deployed. Camels can be driven back, or at least out of
the tent, so we are not fated to have to share our life with them forever after. This is in sharp
contrast to the image of slopes that are so slippery that our slide is irreversible, and which
presumably cannot be climbed once the bottom has been reached.
Of course arguments using images of acorns, wedges, floodgates or camels may also fail for
logical reasons: but they are at least not covertly emotive, and they do not rely on a
manipulative and misleading image. It is time for us to tear down the image of the slope, and
expose its undeserved reputation, for if we acquiesce to it we are surely letting the nose of a
camel of nonsense under the tent flap of rational debate.
John Catherwood was one of the speakers at the Annual Conference held in March 2005 focusing on
the Ethics of Stem Cell Research.
References
[1]. Jonas, H, 1974 Against the stream: comments on the definition and redefinition of death. In
Philosophical essays - from ancient creed to technological man, 132-140. Prentice Hall.
[2]. e.g. we now take organs from brain dead donors, and think it right to do so, despite Hans
Jonas warnings in “Against the stream: comments on the definition and redefinition of death.”
Philosophical essays - from ancient creed to technological man, 132-140, Prentice Hall, 1974.

[3]. Like a SETI@Home screensaver graphic