Pareto argues that people often act first from emotion, habit or perceived self-interest and only afterwards construct rational explanations for what they have done. In this view, reasoning does not always determine behaviour; it can instead provide a convincing justification for choices whose underlying causes lie elsewhere.

He goes further by suggesting that disproving one such explanation may not change the behaviour itself. If the sentiments or interests supporting an action remain unchanged, another theory can be adopted to justify the same position. The argument therefore distinguishes between the stated reasons for conduct and the motives that Pareto believed may actually sustain it.

The passage reflects Pareto’s wider interest in non-logical action and rationalisation. It can be applied cautiously when examining political, social or personal arguments, particularly where explanations appear to change while the underlying preference or behaviour remains constant.