Just war theory deals with the justification of how and why wars are fought. The justification can be either theoretical or historical. The theoretical aspect is concerned with ethically justifying war and the forms that warfare may or may not take. The historical aspect, or the “just war tradition,” deals with the historical body of rules or agreements that have applied in various wars across the ages. For instance, international agreements such as the Geneva and Hague conventions are historical rules aimed at limiting certain kinds of warfare which lawyers may refer to in prosecuting tra...

The logical relation of numerical sameness, in which each thing stands only to itself. Although everything is what it is and not anything else, philosophers try to formulate more precisely the criteria by means of which we may be sure that one and the same thing is cognized under two different descriptions or at two distinct times. Leibniz held that numerical identity is equivalent to indiscernibility or sameness of all the features each thing has. But Locke maintained that judgments of identity are invariably made by reference to types or sorts of things. The identity of individual persons is...

One can scarcely imagine a figure with a greater reputation for disapproval of philosophy than John Calvin. The French expatriate penned some of the most vitriolic diatribes against philosophy and its role in scholastic theology ever written. Thus, in one way, this reputation is rather well-earned, and an article upon Calvin in an encyclopedia of philosophy can be rather brief. However, in another way, Calvin’s consideration, knowledge, and use of philosophy in his own work refutes the obscurantist representation left by a surface-level reading. A closer reading of Calvin’s great work, the...

Affirming the consequent, sometimes called converse error, is a formal fallacy, committed by reasoning in the form: If P, then Q. Q. Therefore, P. Arguments of this form are invalid, in that arguments of this form do not always give good reason to establish their conclusions, even if their premises are true. The name affirming the consequent derives from the premise Q, which affirms the “then” clause of the conditional premise. One way to demonstrate the invalidity of this argument form is with a counterexample with true premises but an obviously false conclusion. For example: If Bill Gate...

The principle of double effect is a set of ethical criteria for evaluating the permissibility of acting when one’s otherwise legitimate act (for example, relieving a terminally ill patient’s pain) will also cause an effect one would normally be obliged to avoid (for example, the patient’s death.) Double-effect originates in the thought of Thomas Aquinas (in his treatment of homicidal self-defense found in his Summa Theologiae, IIa-IIae Q. 64, art. 7). This set of criteria states that an action having foreseen harmful effects practically inseparable from the good effect is justifiable if ...