One account Locke unambiguously rejected from the outset is the supposition that human knowledge is innately inscribed. Noting the remarkably wide-spread agreement of individual human beings in their acceptance of both speculative and practical principles, the innatist argues that universal consent implies an innate origin. Locke's response was two-fold: He denied the supposed fact of universal consent, supposing this to demonstrate the falsity of the innatist view. What is more, Locke argued that if there were any genuine instances of universal consent, they would more naturally be explained by universal possession of an intellectual faculty or by acquisition through some universal experience.
Granting that if general truths about logic were innately know by all human beings, then they must also be universally accepted, Locke emphatically denied the consequent. If the innatists were correct, then children and idiots would be the most pure and reliable guides to logical truth, but they are not. Of course the innatist reply to such counter-examples is to suppose that assent to innately inscribed principles is delayed until each individual is able to employ the faculty of reasoning. But why should this be? Either reason is necessary for the discovery of such principles, in which case they are not innately known, Locke argued, or else reason and logic are merely coincidental features of human development, in which case both seem frivolous. Surely, in fact, the use of reason is properly concerned with our assent to general truths.
Although the senses are necessary for all our knowledge, they are not sufficient to give us all of it, since the senses never give us anything but instances, that is, particular or individual truths. Now all the instances confirming a general truth, however numerous they may be, are not sufficient to establish the universal necessity of that same truth, for it does not