Language is a system that consists of the development, acquisition, maintenance and use of complex systems of communication, particularly the human ability to do so; and a language is any specific example of such a system.
Speech is the vocalized form of communication used by humans and some animals, which is based upon the syntactic combination of items drawn from the lexicon. Each spoken word is created out of the phonetic combination of a limited set of vowel and consonant speech sound units (phonemes). These vocabularies, the syntax that structures them, and their sets of speech sound units differ, creating many thousands of different, and mutually unintelligible, human languages. The vocal abilities that enable humans to produce speech also enable them to sing.
Therapy (often abbreviated tx, Tx, or Tx) is the attempted remediation of a health problem, usually following a diagnosis. In the medical field, it is usually synonymous with treatment (also abbreviated tx or Tx). Among psychologists and other mental health professionals, including psychiatrists, psychiatric nurse practitioners, counselors, and clinical social workers, the term may refer specifically to psychotherapy (sometimes dubbed 'talking therapy'). The English word therapy comes via Latin therapīa from Greek: θεραπεία and literally means "curing" or "healing".
Language is the only instrument of science, and words are but the signs of ideas.
Samuel Johnson, Preface to his English Dictionary.
Henry Drummond: Language is a poor enough means of communication. I think we should use all the words we've got. Besides, there are damned few words that anybody understands!
Inherit the Wind (1960 film), Jerome Lawrence and Robert Edwin Lee
Just at the age 'twixt boy and youth,
When thought is speech, and speech is truth.
Walter Scott, Marmion (1808), Canto II. Introduction.