“ So that, in respect of the act of willing, a man is not free: liberty consisting in a power to act or not to act; which, in regard of volition, a man, has not. ”
 John Locke, An Essay Concerning Human Understanding (1689). copy citation

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“For, it being unavoidable that the action depending on his will should exist or not exist, and its existence or not existence following perfectly the determination and preference of his will, he cannot avoid willing the existence or non-existence of that action; it is absolutely necessary that he will the one or the other; i.e. prefer the one to the other: since one of them must necessarily follow; and that which does follow follows by the choice and determination of his mind; that is, by his willing it: for if he did not will it, it would not be. So that, in respect of the act of willing, a man is not free: liberty consisting in a power to act or not to act; which, in regard of volition, a man, has not. 24. Liberty is freedom to execute what is willed.
This, then, is evident, That A MAN IS NOT AT LIBERTY TO WILL, OR NOT TO WILL, ANYTHING IN HIS POWER THAT HE ONCE CONSIDERS OF: liberty consisting in a power to act or to forbear acting, and in that only.” source