For in much wisdom is much grief: and he that increaseth knowledge increaseth sorrow.

Because In much wisdom there is much indignation: and he that addeth knowledge, addeth also labour.

For in much wisdom is much vexation, and he that increaseth knowledge increaseth sorrow.

for, in abundance of wisdom is abundance of sadness, and he who addeth knowledge addeth pain.'

Because in much wisdom is much grief, and increase of knowledge is increase of sorrow.

Because of this, with much wisdom there is also much anger. And whoever adds knowledge, also adds hardship.

We become more sensible of our ignorance and impotence, and therefore sorrowful, in proportion as we discover more of the constitution of nature and the scheme of Providence in the government of the world; every discovery serving to convince us that more remains concealed of which we had no suspicion before.

For in much wisdom is much grief - The more we know of ourselves the less satisfied shall we be with our own hearts; and the more we know of mankind the less willing shall we be to trust them, and the less shall we admire them.
Be that increaseth knowledge increaseth sorrow - And why so? Because, independently of God, the principal objects of knowledge are natural and moral evils.
The Targum gives a curious paraphrase here: "The man who multiplies wisdom, when he sins and is not converted to repentance, multiplies the indignation of God against himself; and the man who adds science, and yet dies in his childhood, adds grief of heart to his relatives." A man in science; a foolish child in conduct. How pained must they be who had the expense of his education! But there are many men-children of this sort in every age and country.

For in much wisdom [is] much (m) grief: and he that increaseth knowledge increaseth sorrow.
(m) Wisdom and knowledge cannot be come by without great pain of body and mind: for when a man has attained the highest, yet is his mind never fully content: therefore in this world is no true happiness.

For in much wisdom is much grief,.... In getting it, and losing it when it is gotten: or "indignation" (t), at himself and others; being more sensible of the follies and weakness of human nature;
and he that increaseth knowledge increaseth sorrow: for, the more he knows, the more he would know, and is more eager after it, and puts himself to more pains and trouble to acquire it; and hereby becomes more and more sensible of his own ignorance; and of the difficulty of attaining the knowledge he would come at; and of the insufficiency of it to make him easy and happy: and besides, the more knowledge he has, the more envy it draws upon him from others, who set themselves to oppose him, and detract from his character; in short, this is the sum of all human knowledge and wisdom, attained to in the highest degree; instead of making men comfortable and happy, it is found to be mere vanity, to cause vexation and disquietude of mind, and to promote grief and sorrow. There is indeed wisdom and knowledge opposite to this, and infinitely more excellent, and which, the more it is increased, the more joy and comfort it brings; and this is wisdom in the hidden part; a spiritual and experimental knowledge of Christ, and of God in Christ, and of divine and evangelical truths; but short of this knowledge there is no true peace, comfort, and happiness. The Targum is,
"for a man who multiplies wisdom, when he sins and does not turn by repentance, he multiplies indignation from the Lord; and he who increases knowledge, and dies in his youth, increases grief of heart to those who are near akin to him.''
(t) "multa ira", Pagninus, Montanus; "indignatio", V. L. Tigurine version, Vatablus, Drusius; "multum indignationis", Junius & Tremellius, Piscator.

wisdom . . . knowledge--not in general, for wisdom, &c., are most excellent in their place; but speculative knowledge of man's ways (Ecclesiastes 1:13, Ecclesiastes 1:17), which, the farther it goes, gives one the more pain to find how "crooked" and "wanting" they are (Ecclesiastes 1:15; Ecclesiastes 12:12).
He next tries pleasure and luxury, retaining however, his worldly "wisdom" (Ecclesiastes 3:9), but all proves "vanity" in respect to the chief good.

"For in much wisdom is much grief; and he that increaseth knowledge increaseth sorrow." The German proverb: "Much wisdom causeth headache," is compared, Ecclesiastes 12:12, but not here, where כּעס and מכאוב express not merely bodily suffering, but also mental grief. Spinoza hits one side of the matter in his Ethics, IV 17, where he remarks: "Veram boni et mali cognitionem saepe non satis valere ad cupiditates coercendas, quo facto homo imbecillitatem suam animadvertens cogitur exclamare: Video meliora proboque, deteriora sequor." In every reference, not merely in that which is moral, there is connected with knowledge the shadow of a sorrowful consciousness, in spite of every effort to drive it away. The wise man gains an insight into the thousand-fold woes of the natural world, and of the world of human beings, and this reflects itself in him without his being able to change it; hence the more numerous the observed forms of evil, suffering, and discord, so much greater the sadness (כּעס, R. כס, cogn. הס, perstringere) and the heart-sorrow (מכאוב, crve-cour) which the inutility of knowledge occasions. The form of 18a is like Ecclesiastes 5:6, and that of 18b like e.g., Proverbs 18:22. We change the clause veyosiph daath into an antecedent, but in reality the two clauses stand together as the two members of a comparison: if one increaseth knowledge, he increaseth (at the same time) sorrow. "יוסיף, Isaiah 29:14; Isaiah 38:5; Ecclesiastes 2:18," says Ewald, 169a, "stands alone as a part. act., from the stem reverting from Hiph. to Kal with י instead of ." But this is not unparalleled; in הן יוסיף the verb יוסף is fin., in the same manner as יסּד, Isaiah 28:16; תּומיך, Psalm 16:5, is Hiph., in the sense of amplificas, from ימך; יפיח, Proverbs 6:19 (vid., l.c.), is an attribut. clause, qui efflat, used as an adj.; and, at least, we need to suppose in the passage before us the confusion that the ē of kātēl (from kātil, originally kātal), which is only long, has somehow passed over into î. Bttcher's remark to the contrary, "An impersonal fiens thus repeated is elsewhere altogether without a parallel," is set aside by the proverb formed exactly thus: "He that breathes the love of truth says what is right," Proverbs 12:17.

Grief - Or, displeasure within himself, and against his present condition. Sorrow - Which he does many ways, because he gets his knowledge with hard and wearisome labour, both of mind and body, with the consumption of his spirits, and shortening of his life; because he is often deceived with knowledge falsely so called, and often mistakes error for truth, and is perplexed with manifold doubts, from which ignorant men are wholly free; because he hath the clearer prospect into, and quicker sense of his own ignorance, and infirmities, and disorders, and withal how vain and ineffectual all his knowledge is for the prevention or removal of them; and because his knowledge is very imperfect and unsatisfying, yet increasing his thirst after more knowledge; lastly, because his knowledge quickly fades and dies with him, and then leaves him in no better, and possibly in a much worse condition than the meanest and most unlearned man in the world.