Hobbes has defined and illustrated this liberty in a clearer manner than any of its advocates: "I conceive," says he, "liberty to be rightly defined,--the absence of all impediments to action, that are not contained in the nature and intrinsical quality of the agent. As for example, the water is said to descend _freely_, or is said to have liberty to descend by the channel of the river, because there is no impediment that way; but not across, because the banks are impediments: and though water cannot ascend, yet men never say, it wants the _liberty_ to ascend, but the _faculty_ or _power_, because the impediment is in the nature of the water, and intrinsical. So also we say, he that is tied, wants the _liberty_ to go, because the impediment is not in him, but in his hands; whereas, we say not so of him who is sick or lame, because the impediment is in himself,"--that is, he wants the faculty or power of going:--this constitutes natural _inability_. Liberty is volition acting upon physical instrumentalities, or upon mental faculties, according to a fixed and constituted law of antecedents, and meeting with no impediment or overcoming antagonistic power. Natural ability is the fixed and constituted antecedence itself. Hence there may be natural ability without liberty; but liberty cannot be affirmed without natural ability. Both are necessary to constitute responsibility. Natural ability is volition known as a stated antecedent of certain effects. Liberty is this antecedent existing without impediment or frustration. Since this is the only possible liberty remaining, and as they have no wish to be considered fatalists, they enlarge much upon this; not only as the whole of liberty actually existing, but as the full and satisfactory notion of liberty. In basing responsibility and praise and blameworthiness upon this liberty, an appeal is made to the common ideas, feelings, and practices of men. Every man regards himself as free when he does as he pleases,--when, if he pleases to walk, he walks,--when, if he pleases to sit down, he sits down, &c. if a man, in a court of justice, were to plead in excuse that he committed the crime because he pleased or willed to do it, the judge would reply--"this is your guilt, that you pleased or willed to commit it: nay, your being pleased or willing to commit it was the very doing of it." Now all this is just. I readily admit that we are free when we do as we please, and that we are guilty when, in doing as we please, we commit a crime.