It is not of course necessary for people to define pedantically to themselves the meaning of every word they use, but surely it must conduce to clear thinking to use a language in which you are perpetually called upon, if you are writing seriously, to make just the mental effort necessary to think what you do mean.
Again, consider the use of prepositions. This is, in nearly all national languages, extremely fluctuating and arbitrary. Take a few English phrases showing the use of the prepositions "at" and "with." "At seven o'clock"; "at any price"; "at all times"; "at the worst"; "let it go at that"; "I should say at a guess," etc. "Come with me"; "write with a pen"; "he came with a rush"; "things are different with us"; "with a twinkle in his eye"; "with God all things are possible," etc. Try to turn these phrases into any language you think you know; the odds are that you will find yourself "up against it pretty badly." The fact is, that prepositions are very frequently used on no logical plan, not at all according to any fixed or universal meaning; all that can be said about them in a given phrase is that they are used there because they are used. To remember their equivalents in other languages hard memory work and much phrase-learning is necessary. In Esperanto all that is necessary is: first, to become clear as to the exact meaning; secondly, to pick the preposition that conveys it. There is no doubt, as the Esperanto prepositions are fixed in sense, on the "one word one meaning" plan. The point is, that there is no memory searching, often so utterly vain, for there are few people indeed who can write a few pages of the most familiar foreign languages without getting their prepositions all wrong, and having "foreigner" stamped large all across their efforts. In Esperanto, provided you have a clear mind and know your grammar, _you are right_. No arbitrary usage defeats your efforts and makes discouraging jargon of your literary attempts.
This training in clear thought, the first requisite for all good writing, is surely sound practical pedagogics. By the time you can give up conscious word-building in Esperanto, and use words and phrases by rote, you have done enough bracing thinking to teach you caution in the use of the ready-made phrase and horror of the vague word.