Leonardo’s statement presents perception as the starting point of human knowledge. What people see, hear, touch and otherwise experience provides the material from which they form ideas about the world. In this view, understanding begins with contact between the senses and observable reality rather than with abstract reasoning alone.

The quote is closely related to questions in epistemology about how knowledge is acquired and justified. It also reflects Leonardo’s emphasis on careful observation in his artistic and scientific investigations. Perception does not necessarily produce complete or infallible knowledge, because sensory impressions can be limited or mistaken, but it supplies evidence that can then be examined through comparison and reasoning.

The statement can therefore be applied to scientific enquiry, education and everyday judgement. It encourages attention to evidence and direct observation while recognising that perception is the beginning of understanding rather than necessarily its final form.