The concept of apparatus of sensitization allows us to conduct empirical investigations of material supports, combination of objects, public performances which the activists display to arouse emotions predisposing those who are affected to support their cause. As regards the animal cause, historical and ideal type analysis show how the apparatus of sensitization can supply very different emotional registers. The first involves a demopedic logic glorifying the enlightening aims of educators of the animal cause, the second implies a logic of “tenderness” which impels helpers to remedy the immediate suffering of animals deserving affection, and the third supports a logic of “unveiling” leading vindicators to denounce horrifying activities hidden from the public eye. The valorization of one of these emotional registers cannot be exclusively considered as the result of strategic calculations. The article examines how the emotions valued by the activists are an extension of the sensibilities shaped during their own history. It proposes an alternative to the reductive visions of militancy and mobilizations which result from the strategic and utilitarian presuppositions of the political process model.