Philosophers often talk about intuition, and it isn’t always altogether clear what they mean. Many philosophers talk about being sceptical of intuition altogether (which, as I will try to show, is tantamount to an abandonment of classical rationalism and instead a commitment to empiricism). Some silly objections need to pushed out of the way right away. The first is that we don’t know what intuition is, and this is good reason for thinking that we are not justified in using it. There are, of course, two ways to interpret “we don’t know _”, and thus it may depend how we mean that. First, if it means we simply do not have a working understanding of how intuition works, then it can be dealt with quite easily. If, on the other hand, somebody means that they do not even know what ‘intuition’ refers to it is difficult to know exactly where to begin. Bracketing the second scenario for a moment, we can say of the first that: the objection is unreasonable. It is not very controversial to say that we use things like touch and sight all the time, inferring beliefs from both or either without ever needing to inform ourselves about how exactly the processes of sight or touch work. We generally do not think that one needs to have an entire account of how sight or touch work before they can justifiably infer beliefs from their sensitive experience – beliefs which may plausibly be justified. Intuition serves at least as a starting point, such that absent some good reason to think that our intuition is wrong or misleading, we are justified in believing it.
Another objection is that intuition is known to regularly inspire false beliefs. That is to say, in contrast to processes like sight or touch, the beliefs which we infer from our intuitive experience are not reliably generated. This seems, at first blush, to be a more powerful objection, but I don’t think it is much more persuasive. One can, for instance, call into question whether it is really our intuitions which lead us to false beliefs. Moreover, it may still be axiomatic that we need to begin somewhere, and intuition is the only possible place to begin. Critics who don’t recognize this point are, I suspect, operating with a different definition of intuition than the one most ‘Rationalists’ are. For instance, Gottfried Leibniz, in his New Essays on Human Understanding, Book IV, defines intuition as follows:
Knowledge is intuitive when the mind perceives that two ideas agree or disagree, seeing this just by considering them and without help from any third idea serving as a link between them. Intuitive knowledge doesn’t involve any work of proving or examining the truth that is known. As ·immediately· as the eye sees light, the mind perceives that white is not black, a circle is not a triangle, three is one and two.
It is difficult to see where else one is to begin than those things which are perceived immediately and self-evidently by the mind. Notice that this definition differs (or must differ) quite a lot from whatever the critic has in mind. Now, often times people will say they have intuitions about things like the laws of logic. For instance one might say that they have an intuition (immediately perceive in the mind) that what the law of non-contradiction stipulates is true (laws cannot be true or false). Alternatively a philosopher might say that their intuition compels them to believe in causes in the world, or at least in the Principle of sufficient reason (without which even predication in language might be rendered senseless). The list goes on, but I suspect the point is clear. Somebody may say that their intuition leads them to disbelieve, say, in the PSR but in that case they are appealing to intuition just the same. Alternatively somebody can call into question whether another person’s intuition really is leading them to believe in some belief ‘x’, or whether there is some linguistic or other confusion/factor which can account for their belief along with why they suspected the belief to be intuitive.
Ultimately I defend intuition as being an epistemological starting point, and I suggest that beliefs which are intuitive ought always to be believed, except in the presence of some defeater.