	In the sixth paragraph of the sixth meditation, Descartes gives several examples of what he considers to be natural inclinations. The examples he gives are all of the same form - the body feels a sensation and this gives rise to a particular thought. 
 Other cases he mentions include hunger and thirst.
	Regarding these inclinations, Descartes says that he never had to think about whether they were correct, that he had already decided they were true before attempting to prove them. The use of the word "prove" and the whole idea that an inclination could be true or false is problematic. It makes sense to say a proposition about reality is true or false, because you can look to see if you are right, or can at least imagine that reality has some type of structure that someone, looking from a certain (maybe impossible) vantage point and seeing certain properties, could say that the statement is true or false. To say that there are three types of neutrinos is a statement which is either true or false because you can imagine at least a model of neutrinos and there being three different kinds. Maybe there is nobody small enough to look at neutrinos and see if they come in three types, and maybe it is even physically impossible to construct a machine that could probe such small sizes, but the proposition makes sense because you can imagine that if it were possible to look, you could see whether they come in three types. But the proposition "if you feel a particular pulling sensation in your stomach, you should eat" is not, because the proposition "you should eat" is not a fact about reality and does not have a truth value. I cannot even imagine a science-fiction way in which the statement "you should eat" could be verified. It is true that if you don't eat (for a while) you'll die, but this is a different statement.
	Descartes confuses the issue by treating these inclinations like things that are true or false. What he should be wondering is why there is the connection between the sensation and the following disposition. Why is it that when he begins to feel the "tugging sensation" in his stomach he begins thinking of ways to obtain food? Descartes is probably at least semi-correct in supposing these associations to be innate. Psychologists and biochemists know that there are particular chains of chemical release associated with hunger causing you to eat and satiety causing you to stop eating. Your stomach being empty physically causes the release of some chemical which releases another chemical and somewhere along the chain, neural mechanisms for finding and ingesting food are activated. But psychologists also know that everything you do is associated with some chemical event in the brain, and surely some of these chemical events/human actions can be thought of as learned behavior. 
