There can be no doubt that Darwin’s influence over his friends was very great, probably all the more so because he was so unassertive and disinclined to interfere or to dictate. Sir John Lubbock is said to have ‘owed to the great Charles Darwin even a larger debt in the respect of character formation than in the encouragement and direction of his mental gifts.’[225] Darwin did not hesitate to advise urgently and warmly, where he felt that advice was needed. For example, he writes to Hooker about his health: ‘Take warning by me, and do not work too hard. For God’s sake, think of this.’[226] He did not hesitate to differ, or to question, or to argue, when he thought his friends were wrong, and he could set them right. At the same time, owing to his humility and natural self-effacement, the chief impression one gets from the intimate personal correspondence is that of turning to friends for counsel, encouragement, and support. Not that he was not amply able and ready to stand on his own feet; but to develop his views and arguments to others seemed to clarify them and to give them added force and significance for himself: ‘I will write no more, which is a great virtue in me; for it is to me a very great pleasure telling you everything I do.’[227] Honor, commendation, appreciation, when they came from the public, were all very well; but their value and their charm were doubled when they came from those one loved. Thus, he writes in regard to a letter of Hooker, congratulating him on the receipt of a medal: ‘I then opened yours, and such is the effect of warmth, friendship, and kindness from one that is loved, that the very same fact, told as you told it, made me glow with pleasure till my very heart throbbed.’[228] I have already alluded to his expressions of gratitude and appreciation for all the support and assistance that his friends gave him; but the expression is so tender, and so constant, and so thoroughly characteristic, that it cannot be too much insisted upon.