A dictionary of Proverbs (Oxford Paperback Reference)

You never KNOW what you can do till you try
□1818 COBBETT Year’s Residence in USA II. vi. A man knows not what he can do ‘till he tries. 1890 M. WILLIAMS Leaves of Life I. xiii. On hearing the verdict he.. shouted out: ‘I told you so! You never know what you can do till you try’. 1968 D. FRANCIS Forfeit xiv. ‘Ty, you aren’t fit to drive.’ ‘Never know what you can do till you try.’ “boldness
know see also BETTER the devil you know than the devil you don’t know; the FROG in the well knows nothing of the sea; one HALF of the world does not know how the other half lives; the HUSBAND is always the last to know; come LIVE with me and you’ll know me; MORE people know Tom Fool than Tom Fool knows; NECESSITY knows no law; it TAKES one to know one; it’s not WHAT you know, it’s who you know; it is a WISE child that knows its own father; see also KNEW; KNOWN.
knoweth see the FAT man knoweth not what the lean thinketh.
KNOWLEDGE is power
Similar in form to MONEY is power and similar in sentiment to PROVERBS xxiv. 5 (AV) A man of knowledge increaseth strength. Cf. 1597 BACON De Haeresibus x. nam et ipsa scientia potestas est, for knowledge itself is power.

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  1598 in Bacon Essays 27V Knowledge it selfe is a power whereby he [God] knoweth. 1806 B. RUSH Letter 25 Nov. (1951) II. 935 The well-known aphorism that ‘knowledge is power.’ 1853 BULWER-LYTTON My Novel I. II. iii. He.. said half aloud,—’Well, knowledge is power!’ 2002 Washington Post 11 Mar. A21 The assumption seems to be that if we can explain the powerful forces that control our lives, we become somehow immune to them. Knowledge, as they say, is power. "power; wisdom
  

knowledge see also a LITTLE knowledge is a dangerous thing.
known see a CARPENTER is known by his chips; a man is known by the COMPANY he keeps; the TREE is known by its fruit.