There is direction of resolutions as well as direction of a journey; it is necessary, from the beginning, to consider well the choice of a good route, after having done everything possible to discriminate carefully between it and all other routes proposed.
It happens, however, that the way leads also through the cross-roads; it is even indispensable to leave the short cuts in order to trace the outline of the obstacles.
Direction is, then, an important factor in the acquiring of common sense.
The putting of the question takes its character from comparison, from experience, and principally from approximation; but it is in itself a synthesis of all the elements which compose common sense.
He who wishes to acquire common sense should be impregnated with all that has preceded.
Then he will discipline himself, so as to be able to judge, by himself, of the degree of reason which he has the right to assume.
He will begin by evoking some subject, comparing its visual forms with, those forms which he understands the best, in other words, to the perceptions which are the most familiar to him.
If it concerns a question to be solved, he will try to recall some similar subject, and establish harmony, by making them both relative to a common antecedent.
Yoritomo advises choosing simple thoughts for the beginning.
"One will say, for example:
"Such a substance is a poison; the seeds of this fruit contain a weak dose of it; these seeds could then become a dangerous food, if one absorbed a considerable quantity.
"Common sense will thus indicate a certain abstaining from eating of it.
"Then one may extend his argument to things of a greater importance, but taking great care to keep within the narrow limits of rudimentary logic.
"One must be impregnated with this principle:
"Two things equal to a third demand an affirmative judgment or decision.
"In the opposite case the negative deduction is enjoined.
"It is by deductions from the most ordinary facts that one succeeds in making common sense intervene automatically in all our judgments.
"What would be thought of one who, finding himself in a forest at the time of a violent storm, would reason as follows:
"First: The high summits attract lightning.
"Secondly: Here is a giant tree.
"Thirdly: I'm going to take refuge there.
"Then it is that common sense demands that the state his three propositions as follows:
"First: High summits attract lightning.
"Secondly: Here is a giant tree.
"Thirdly: I'm going to avoid its proximity because it will surely be dangerous.
"If he acted otherwise; if, in spite of his knowledge of the danger, he took shelter under the branches of the gigantic tree, exposing himself to be struck by lightning, one could, in this case, only reproach him with imprudence and lay the blame to the lack of common sense which allowed him to perform the act that logic condemned."
Now the old Nippon speaks to us of the means to employ, that we may avoid pronouncing too hasty judgments, which are always, of necessity, weakened by a too great indulgence for ourselves and at the same time too great a severity for others.
"I was walking one day," said he, "on the shores of a lake, when I discovered a man sitting at the foot of a bamboo tree, in an attitude of the greatest despair.
"Approaching him, I asked him the cause of his grief.
"'Alas!' said he to me, 'the gods are against me; everything which I undertake fails, and all evils crush me.
"'After the one which has just befallen me only one course of action is left to me, to throw myself in the lake. But I am young, and I am weeping for myself before resolving to take such a step.'
"And he related to me how, after many attempts without success, he had at last gained a certain sum of money, the loss of which he had just experienced.
"In what way did you lose it?" I asked him.
"'I put it in this bag.'
"'Has some one stolen it?'
"'No, it has slipt through this rent.'
"And he showed me a bag, whose ragged condition confirmed, and at the same time illustrated his statement.
"'Listen,' said I, sitting down beside him, 'you are simply devoid of common sense, by invoking the hatred of the gods! You alone are the cause of your present misery.
"'If you had simply reasoned before placing your money in this bag, this would not have happened to you.'
"And as he opened his eyes wide:
"'You would have thought this,' I resumed:
"'The material, very much worn, is incapable of standing any weight without tearing.
"'Now, the money which I possess is heavy, my bag is worn out.
"'I shall not, therefore, put my money in this bag or, at least, I shall take care to line it beforehand with a solid piece of leather.
"'From this moment,' I proceeded, 'there only remains one thing for you to do, always consult common sense before coming to any conclusion, and you will always succeed.
"'As for your opinion concerning the hatred of the gods for you, if you will once more call common sense to your assistance you will reason as follows:
"'Gracious divinities protect only wise people.
"'Now, I have acted like a fool.
"'It is, therefore, natural that they should turn away from me.'
"How many useless imprecations would be avoided," adds the Shogun, "if it were given to men to know how to employ the arguments which common sense dictates, in order to distribute the weight of the mistakes committed among those who deserve the burden, without, at the same time, forgetting to assume our own share of the responsibility if we have erred.