reasoned that this was possible because Socrates' questions sparked the innate knowledge of math the boy had from birth. Descartes Descartes conveys the idea that innate knowledge or ideas is something inborn such as one would say, that a certain disease might be 'innate' to signify that a person might be at risk of contracting such a disease. He suggests that something that is 'innate' is effectively present from birth and while it may not reveal itself then, is more than likely to present itself later in life. Descartes’ comparison of innate knowledge to an innate disease, whose symptoms may only show up later in life, unless prohibited by a factor like age or puberty, suggests that if an event occurs prohibiting someone from exhibiting an innate behaviour or knowledge, it doesn't mean the knowledge did not exist at all but rather it wasn't expressed – they were not able to acquire that knowledge. In other words, innate beliefs, ideas and knowledge require experiences to be triggered or they may never be expressed. Experiences are not the source of knowledge as proposed by John Locke, but catalysts to the uncovering of knowledge. Gottfried Wilhelm Leibniz Gottfried Wilhelm Leibniz suggested that we are born with certain innate ideas, the most identifiable of these being mathematical truisms. The idea that 1 + 1 = 2 is evident to us without the necessity for empirical evidence. Leibniz argues that empiricism can only show us that concepts are true in the present; the observation of one apple and then another in one instance, and in that instance only, leads to the conclusion that one and another equals two. However, the suggestion that one and another will always equal two requires an innate idea, as that would be a suggestion of things unwitnessed. Leibniz called such concepts as mathematical truisms "necessary truths". Another example of such may be the phrase, "what is, is" or "it is impossible for the same thing to be and not to be". Leibniz argues that such truisms are universally assented to (acknowledged by all to be true); this being the case, it must be due to their status as innate ideas. Often there are ideas that are acknowledged as necessarily true but are not universally assented to. Leibniz would suggest that this is simply because the person in question has not become aware of the innate idea, not because they