acts of worship because he lacks reason, then his contracts are all the more clearly invalid, as with someone asleep, someone insane, and others like them. Indeed, a person’s acts of worship may be valid even though his legal acts are invalid because of his deficient reason, as with a child or someone placed under legal restriction for prodigality.

“The third”

All utterances and contracts depend upon the presence of discernment and reason. The words of someone who has neither discernment nor reason carry no weight whatsoever in Islamic law. As the Prophet, peace and blessings be upon him, said:

“Indeed, in the body there is a morsel of flesh: when it is sound, the rest of the body is sound, and when it is corrupt, the rest of the body is corrupt. Truly, it is the heart.”

If the heart has lost the reason by which a person speaks and acts, how can legal effect be given to his commands and prohibitions, or to his establishment or termination of ownership? This is known through reason and affirmed by the Lawgiver.

“And the fourth”

Contracts and other legal acts depend upon intentions. As the Prophet, peace and blessings be upon him, said:

“Actions are only according to intentions.”

I have established this principle in Bayān al-Dalīl ʿalā Butlān al-Tahlīl (Exposition of the Evidence for the Invalidity of Tahlīl). I have also established that any utterance made without the speaker intending it—because of inadvertence, a slip of the tongue, or lack of reason—has no legal consequence. As for someone who intends the words but not their meaning, such as someone speaking in jest, this requires further distinctions.

What is meant here by “intention” is rational intention, which is specific to the faculty of reason. As for the animal intention possessed by every animal, this is indispensable to the occurrence of voluntary words and deeds. Yet this alone is insufficient for contracts and utterances to be valid, for the insane, children, and others possess