“Even the wisest among us do not possess complete knowledge of every subject; however, they acquire a deep understanding regarding the limits of their knowledge. Acknowledge, the extent of your knowledge.
RJ Intindola – (Gandolfo) – 1994”
Related quotes

Source: Kritik der zynischen Vernunft [Critique of Cynical Reason] (1983), p. 77
Paul Cilliers (2005: 263) as quoted in: Vikki Bell (2007) Culture and Performance: The Challenge of Ethics, Politics and Feminist Theory. p. 8

Introduction
Popular Astronomy: A Series of Lectures Delivered at Ipswich (1868)

“Within the extent of your knowledge, you are right.”
“Knowledge can be acquired by a suitable and complete study, no matter what the starting point is.”
All and Everything: Views from the Real World (1973)
Context: Knowledge can be acquired by a suitable and complete study, no matter what the starting point is. Only one must know how to "learn." What is nearest to us is man; and you are the nearest of all men to yourself. Begin with the study of yourself; remember the saying "Know thyself."

Maxim no .1.
The Maxims of Ptahhotep (c. 2350 BCE)
Context: Do not be arrogant because of your knowledge, but confer with the ignorant man as with the learned. For knowledge has no limits, and none has yet achieved perfection in it. Good speech is more hidden than malachite, yet it is found in the possession of women slaves at the millstones.