The Romans frequently had two generals, or consuls, to command their armies in the field: one of which was to be a young man, that by his vigour and sprightly forwardness he might keep up the spirits and courage of the soldiers, encourage them to fight, and lead them on by his example; the other an old soldier, that by his experience in the military affairs, age, and counsels, he might a little abate the fire of his colleague, and might not only know how to fight, but know when to fight, that is to say, when to avoid fighting; and the want of this lost them many a victory, and the great battle of Cannae in particular, in which 80,000 Romans were killed in one day.
To compare small things with great, I may say it is just so in the affair of trade.

You should always join a sober grave head, weighed to business, and acquainted with trade, to the young trader, who having been young in the work will the easier give up his judgment to the other, and who is governed with the solid experience of the other; and so you join their ways together, the rash and the sedate, the grave and the giddy.
Again, if you must go into partnership, be sure, if possible, you take nobody into partnership but such as whose circumstances in trade you are fully acquainted with.

Such there are frequently to be had among relations and neighbours, and such, if possible, should be the man that is taken into partnership, that the hazard of unsound circumstances may be avoided.

A man may else be taken into partnership who may be really bankrupt even before you take him; and such things have been done, to the ruin of many an honest tradesman.
If possible, let your partner be a beginner, that his stock may be reasonably supposed to be free and unentangled; and let him be one that you know personally, and his circumstances, and did know even before you had any thoughts of engaging together.
All these cautions are with a supposition that the partner must be had; but I must still give it as my opinion, in the case of such tradesmen as I have all along directed myself to, that if possible they should go on single-handed in trade; and I close it with this brief note, respecting the qualifications of a partner, as above, that, next to no partner, such a partner is best..