No man’s knowledge here can go beyond his experience.

This line expresses John Locke’s empiricist program in the late seventeenth century, developed most fully in his Essay Concerning Human Understanding (1690). Writing against the view that the mind contains innate ideas, Locke argues that the materials of thought originate in experience—either from sensation (the external world) or reflection (the mind’s awareness of its own operations). In this context, claims to knowledge that outrun what experience can supply are treated with suspicion, and Locke urges philosophers to examine the limits of human understanding. The remark belongs to his broader attempt to set boundaries for certainty and to redirect inquiry toward what can be responsibly known.

The quotation encapsulates Locke’s central thesis that knowledge is constrained by experience: we cannot legitimately claim to know what we have not, in some way, encountered through the senses or through introspective awareness of mental activity. It is both a methodological warning and an epistemological limit—encouraging humility about metaphysical speculation and emphasizing careful attention to evidence. The line also implies that differences in what people know often track differences in what they have experienced, making education, observation, and experiment crucial. In Locke’s framework, experience supplies the “ideas” from which reasoning builds; without those materials, purported knowledge becomes mere assertion.