To undertake to learn any trade but his father's would strike the family as simply preposterous.

Why should he adopt another line of business?
And, if he did, what other business should he adopt?
Is his father's occupation not already there, a part of the existing order of things; and is he not the son of his father and heir therefore of the paternal skill?
Not that such inherited aptness is recognized scientifically; it is simply taken for granted instinctively.
It is but a halfhearted intuition, however, for the possibility of an inheritance from the mother's side is as out of the question as if her severance from her own family had an ex post facto effect.

As for his individual predilection in the matter, nature has considerately conformed to custom by giving him none.

He becomes a cabinet-maker, for instance, because his ancestors always have been cabinet-makers.

He inherits the family business as a necessary part of the family name.