Deductive Reasoning Misunderstanding

[Cbsteffen]

I had done a search with deductive reasoning and seemed to think that every property in that case of reasoning had to be true, but I could've been proven wrong. This statement is considered an example of deductive reasoning:

All fruits grow on trees. Oranges are fruits. Therefore, oranges grow on trees.

The truth is, not all fruits grow on trees. Cranberries grow in bogs, and grapes grow on vines. That doesn't mean they're not fruits. Fruits are fertilized from an ovum (probably from what they grow on or in).

Doesn't deductive reasoning mean eliminating whatever does not apply to a theory so a person can reach the right conclusion?

[catherinedwhite]

In layman's terms, there is normally an exception to every rule which throws deductive reasoning out the window for every day topics.
Deductive reasoning is best used in math situations.

[pmagalei]

Deductive reasoning is based on premises. If the premises are true, then the reasoning will be valid. The example of "all fruits grow on trees" was not a good example of deductive reasoning but rather an example of inductive reasoning. Here's an example all numbers ending in 0 or 5 are divisible by 5. therefore number 10 ends with a 0, so it is divisible by 5.

[Cbsteffen]

Deductive reasoning is based on premises. If the premises are true, then the reasoning will be valid. The example of "all fruits grow on trees" was not a good example of deductive reasoning but rather an example of inductive reasoning. Here's an example all numbers ending in 0 or 5 are divisible by 5. therefore number 10 ends with a 0, so it is divisible by 5.

Well, I don't think you can have deductive reasoning without inductive reasoning.