“There are three principal means of acquiring knowledge available to us: observation of nature, reflection, and experimentation. Observation collects facts; reflection combines them; experimentation verifies the result of that combination. Our observation of nature must be diligent, our reflection profound, and our experiments exact. We rarely see these three means combined; and for this reason, creative geniuses are not common.”
Cite this quote
APA
Diderot, D. (n.d.). There are three principal means of acquiring knowledge available to us: observation of nature, reflection, and experimentation. Observation collects facts; reflection combines them; experimentation verifies the result of that combination. Our observation of nature must be diligent, our reflection profound, and our experiments exact. We rarely see these three means combined; and for this reason, creative geniuses are not common. [Quotation]. Famous Quotations Network. Retrieved October 24, 2026, from https://www.famous-quotations.com/quotes/25247-there-are-three-principal-means-of-acquiring-knowledge/
MLA
Diderot, Denis. “There are three principal means of acquiring knowledge available to us: observation of nature, reflection, and experimentation. Observation collects facts; reflection combines them; experimentation verifies the result of that combination. Our observation of nature must be diligent, our reflection profound, and our experiments exact. We rarely see these three means combined; and for this reason, creative geniuses are not common.” Famous Quotations Network, https://www.famous-quotations.com/quotes/25247-there-are-three-principal-means-of-acquiring-knowledge/. Accessed 24 Oct. 2026.
Chicago
Diderot, Denis. “There are three principal means of acquiring knowledge available to us: observation of nature, reflection, and experimentation. Observation collects facts; reflection combines them; experimentation verifies the result of that combination. Our observation of nature must be diligent, our reflection profound, and our experiments exact. We rarely see these three means combined; and for this reason, creative geniuses are not common.” Famous Quotations Network. Accessed October 24, 2026. https://www.famous-quotations.com/quotes/25247-there-are-three-principal-means-of-acquiring-knowledge/.