Very wise folk are generally easily deceived, for while they know out-of-the-way things they do not know the ordinary things of life, which are much more needful... Let therefore the prudent take care to have something of the trader about him... Of what use is knowledge if it is not practical, and to know how to live is nowadays the true knowledge.
Baltasar Gracián, 1647 (tr. Joseph Jacobs, 1892)
Deep knowledge of lofty things is no protection against being cheated in ordinary ones, and often it is the reason. The person absorbed in higher matters frequently has no grip on the everyday arithmetic, the price of things, the terms of a deal, the small practical calculations everyone around them handles without thinking, and so the very learned get fleeced by the merely shrewd. The remedy is to keep a touch of the trader in you: enough street sense not to be deceived and laughed at, enough practical footing to manage the daily round. Knowledge that cannot handle real life is a decoration, and knowing how to actually live, to transact, to not be cheated, is itself a form of intelligence, and in daily practice the more necessary one of the two.
Practice
- Keep a working grip on the practical arithmetic of your life; the price, the terms, the numbers others handle without thinking are exactly where the learned get fleeced.
- Value street sense as real intelligence, not a lesser thing; knowledge that cannot manage daily life is a decoration (maxim 233 reads others' taste in the same practical spirit).
- Check the everyday deal yourself; the habit of leaving the ordinary to others is the habit that gets you cheated.
Use this when
- Use this if your strength is expertise or ideas; that is exactly the profile the shrewd find easiest to deceive on ordinary terms.
- Use it in money and contracts, the daily arithmetic where abstract intelligence offers no protection at all.
Ignore this when
- Don't swing into treating everything as a transaction; the trader's touch is a floor against being cheated, not a whole worldview (maxim 247 keeps time above busyness).
- Don't disdain the practical people around you; the ones fluent in the daily round know something you need (maxim 206 warns against sneering as its own folly).
A picture of it
Brilliant in his field, a professor is repeatedly fleeced in ordinary dealings: overpaying for work on his house, signing a contract whose terms he never read, losing money on arrangements a market trader would have seen through in a minute. His deep knowledge of far-off things left no room for the near ones, and the shrewd learned to bring him their deals precisely because he would not check the arithmetic. Only when he forces himself to acquire a trader's basic caution, reading the terms and asking the price, does the fleecing stop. The learning was never the problem. The missing floor beneath it was.
The highest knowledge is no shield against the oldest tricks. Keep enough of the trader in you not to be cheated at the daily arithmetic.