In deductive reasoning, the subject is assumed to be rational and the deduction of facts is based upon the assumption of the subject. One can start this process by a premise-without-the-hyphens. For example, a student has been asked, “What color shirt does Tom wear?” The student might have a reasonable answer such as “He’s a redhead.” If the student were then to assume that Tom wears red, she could then deductively state, “Based on this premise,” that Tom wears a red-head, “Therefore, Tom wears a red-head shirt.”
Next, the student is allowed to infer from her observations that Tom wears a red-shirt without taking into account her observations about the color. If she finds this fact true, then she has concluded that Tom does wear a red-shirt and this is the end of her deductive reasoning. However, if the student finds the conclusion to be false, she would not conclude that he wears a red-shirt. This is where inductive reasoning comes in.
Inductive reasoning is used to infer the existence or non-existence of certain things based on the existence or non-existence of certain other things. A very common example is where one might assume, without taking into consideration any observations, that “Jane Smith was at the doctor’s office for her regular checkup.” She might then ask her friend, “How many times has your daughter visited the doctor in the last year?” Assuming the assumption, her friend could say, “Jane visits the doctor at least six times every year.”
After assuming the existence of Jane Smith, her friend might then take into consideration that she has had several previous doctors and also the medical conditions that she has had and arrive at the conclusion that she has had six or more trips to the doctor. The assumption could then be considered true based upon the premise and therefore, the conclusion could be drawn that Jane Smith visits the doctor at least six times a year. and therefore, she has had at least six visits. medical conditions.
Now, her friend could further assume that the visits she has made to the doctor were normal and that she did not have any medical conditions that required her to go to the doctor or had the doctor prescribed a medication. If these assumptions are true, then the conclusion of her reasoning could be drawn that she has not visited the doctor at least six times a year and therefore, does not have any medical conditions and therefore does not have to go to the doctor.
If, however, her friend was wrong about her condition then her logic would take into consideration two premises. Her first assumption would be false since she would have two visits, yet this would still give her a reason to visit the doctor because her friend would have two visits. Her second assumption, however, would then require that the second visit, which would not be a medical visit, would need to be treated because if it were a medical visit, then a doctor would have diagnosed it and therefore, it is not necessary for the doctor to treat her condition.
In inductive logic, there is no proof that the premises are true because it is not possible to prove the existence of premises. This means that you must rely on your interpretation of the premises in order to decide the validity of the premises.