What is the definition of intoxication in Texas?

"Intoxication" under Texas law means:
(A) not having the normal use of [one’s] mental faculties by reason of the introduction of alcohol, a controlled substance, a drug, a dangerous drug, a combination of two or more of those substances, or any other substance into the body; or
(B) not having the normal use of [one’s] physical faculties by reason of the introduction of alcohol, a controlled substance, a drug, a dangerous drug, a combination of two or more of those substances, or any other substance into the body; or(C) [a person] having an alcohol concentration of 0.08 or more.
It should be noted, that theoretically the prosecutor only needs to prove one of the three ways in order to obtain a conviction. For example, if the jury believes the person has lost their physical faculties, although they have not lost their mental faculties and there is no blood or breath test, theoretically that person could be found guilty. That is not always the case, generally, if the evidence only shows the loss of either the mental or physical faculties, and not both, there is usually a logical explanation for that loss and the result should be they are not intoxicated.