What is Dicto Simpliciter?

Dicto simpliciter is the fallacy of sweeping generalization. It consists of the application of a broad general rule to an individual case whose special features might make it exceptional. To insist that the generalization must apply to each and every case, regardless of individual differences, is to commit the fallacy of dicto simpliciter.


Of course you voted for the resolution. You’re a dock-worker, and your union cast 120,000 votes in favour.

(Carried unanimously, brothers, and by a clear majority.)


Many of our general statements are not universals. We make them in the full knowledge that there will be cases whose accidental features make them exceptions. We are apt to say that various things make people healthy, knowing that we do not necessarily have to mean ‘all’ people. We make similar generalizations about foods, even though we recognize that some people have allergies to various foodstuffs.

When we insist on treating a generalization as if it were a universal which admitted no exceptions, we commit a dicto simpliciter. The fallacy arises because we use information about the whole of a class, which has not been established or accepted. We bring in outside material, therefore, without justification.


Everyone knows that hooded teenagers are criminals. Since this hooded one isn’t breaking any laws, he must be older than he looks.

(Or maybe he’s just having a day off.)


Dicto simpliciter arises whenever individuals are made to conform to group patterns. If they are treated in tight classes as ‘teenagers’, ‘Frenchmen’, or ‘travelling salesmen’, and are assumed to bear the characteristics of those classes, no opportunity is permitted for their individual qualities to emerge. There are political ideologies which attempt to treat people in precisely this way, treating them only as members of sub-groups in society and allowing them only representation through a group whose values they may not, in fact, share.


Look, you’re a civil servant. Your representatives voted for this action because they know it will be good for the civil service. It must therefore be good for you.

(He only imagined those lost wages.)


In discussing people of whom we have a little knowledge, we often use dicto simpliciter in the attempt to fix onto them the attributes of the groups they belong to. Knowing only that a neighbour is civil to us and drives a better car, we try to deduce things from the fact that he is a Catholic or a squash-player. Our assumption of ancillary properties may, in fact, be correct; the mistake is to suppose that it must be: ‘We all know that children are smaller than their parents. Well, now that I’m 50 and Dad is 80, I’ve noticed that I’m quite a bit taller. Maybe he isn’t my real father.’

Dicto simpliciter can be used to fit people into stereotypical moulds. Since they belong to the class of Frenchmen, balletdancers and horseriders, they must be great lovers, effeminate and bow-legged. You must appeal to generally accepted truisms in order to fill in details about individual cases which would otherwise be resisted.

You should as a parent use dicto simpliciter to trick your child into doing what you want instead of what they want:


Spinach is good for growing children. Eat it up.

(But beware of the construction which says that ‘all good children do such and such’. Your progeny might slip out of the group in question by recognizing themselves as bad.)


The above article is from the book How To Win Every Argument by Madsen Pirie. The article is only for educational and informative purposes to explain and understand formal logic and logical fallacies. It is a great book, definitely worth a read!