Proverbs accordingly are somewhat analogous to those medical Formulas which, being in frequent use, are kept ready-made-up in the chemists’ shops, and which often save the framing of a distinct Prescription. – Richard Whately, Elements of Rhetoric

Apothegms to thinking minds are the seeds from which spring vast fields of new thought, that may be further cultivated, beautified, and enlarged. – Ramsay, as quoted in A Dictionary of Thoughts: A Cyclopedia of Laconic Quotation

Only roam on, therefore, all fearless, in the many garden of romantic chivalrous poesy, which drawing within its circle all that is glorious and inspiring, gave itself but little concern as to where its flowers originally grew. – C.O. Müller (Karl Otfried Müller), Introduction to a Scientific System

Nevertheless, a maxim does not necessarily become a proverb. Many grubs never grow to butterflies; and a maxim is only a proverb in its caterpillar stage—a candidate for a wider sphere and longer flight than most are destined to attain. – “Proverbs Secular and Sacred,” The North British Review, February 1858