Definition
Firmness is the faculty which stands for determination, and persistence, for the connection between principles and acts, for perseverance, determination, resolution, and stamina. A strong Firmness may cause stubbornness and inflexibility. A negative Firmness stands for an insipid character, passivity and lack of decision-making capability.
Localisation
Firmness is located on top of the skull, just behind the perpendicular line drawn from the aural conduct upwards. This line separates Firmness and Veneration.
References
Firmness (phrenology) Wikipedia(Text) CC BY-SA