Circular insanity

Another name for maniacal-depressive insanity, which see.
—Partial insanity, as a legal term, may mean either monomania (see infra) or an intermediate stage in the development of mental derangement.

In the former sense, it does not relieve the patient from responsibility for his acts, except where instigated directly by his particular delusion or obsession. Com. v. Mosler, 4 Pa. 264; Co.m. v. Earner, 199 Pa. 335, 49 Atl. 60; Trich v. Trich, 165 Pa. 586, 30 Ail. 1053.

In the latter sense, it denotes a clouding or weakening of the mind, not inconsistent with some measure of memory, reason, and judgment. But the term, in this sense, does not convey any very definite meaning, since it may range from mere feeble-mindedness to almost the last stages of imbecility. State v. Jones, 50 N. H. 383, 9 Am. Rep. 242; Appeal of Dunham, 27 Conn. 205.
Defined under Insanity in Black's Law Dictionary.