mr spock always uses his head when trying to convince his audience of his viewpoint.  he often began his speech ,  logically speaking.....  what fundamental of persuasion does mr spock use?  ethos, logos, pathos

Mr. Spock primarily uses logos, as he relies on logical reasoning and facts to convince his audience of his viewpoint. Ethos could also be present, as his credibility as a highly intelligent and rational individual may also play a role in persuading others. Pathos, on the other hand, is less likely to be a fundamental of persuasion that Mr. Spock uses, as he tends to rely more on logical arguments rather than emotional appeals.