Some snakes are poisonous. A rattlesnake is a snake. Therefore: a rattlesnake is poisonous. Is syllogism valid or invalid?
Although a rattlesnake is truly poisonous, you don't know in the syllogism if it is included in the "some snakes." Invalid syllogism.
To determine the validity of this syllogism, we need to assess the logical structure of the argument. A syllogism consists of two premises and a conclusion. Let's break it down:
Premise 1: Some snakes are poisonous.
Premise 2: A rattlesnake is a snake.
Conclusion: Therefore, a rattlesnake is poisonous.
This syllogism follows the form of a categorical syllogism, specifically the form of "Some A are B, All B are C, therefore, Some A are C." However, there is an error in the argument. Premise 1 states that only "some snakes are poisonous," but it does not establish the poison status of all snakes, including the rattlesnake mentioned in Premise 2.
Therefore, the syllogism is invalid because it makes a logical leap (in this case, assuming that since some snakes are poisonous, all snakes are poisonous) without adequate support from the premises.