If a valid argument has a false conclusion, then at least one premise must be false. TRUE: A valid argument cannot have all true premises and a false conclusion. So if a valid argument does have a false conclusion, it cannot have all true premises. Thus at least one premise must be false.
What can an argument with false premises be?
An argument from false premises is a line of reasoning which can lead to wrong results. A false premise is an untrue proposition that forms part of the basis of a logical syllogism. Since the premise (assumption) is not correct, the conclusion drawn may also be wrong.
Can an argument be valid if a premise is false?
A valid argument can have false premises; and it can have a false conclusion. But if a valid argument has all true premises, then it must have a true conclusion.
What is the status of an argument whose premises contradict each other and hence Cannot all be true together?
So if your premises are false, your argument is always valid. If your premises contradict, so that they cannot all be true, because if some of them are true, others would not be, then, taken together they are false. So your argument is valid.
What is an unsound argument?
An unsound argument is either an invalid argument or a valid argument with at least one false premise. Page 20. Some Final Notes on Validity and Soundness. A valid argument preserves truth. That is, if we have a valid argument, and if all of the premises are in fact true, then the conclusion will always be in fact true …
Can an argument have all true premises and a true conclusion yet not be deductively valid?
If an argument has all true premises and a true conclusion, then it is valid. FALSE: It is possible for an argument to have all true premises and a true conclusion but still be invalid.
Can an invalid argument have all true premises?
If an argument is invalid, then it must have at least one false premise. If an argument has a conclusion that is certainly false, then the argument must be invalid. If the premises and conclusion are all false, the argument must be invalid. Some invalid arguments have true premises and a true conclusion.
Can premises be valid?
An argument is valid if the premises and conclusion are related to each other in the right way so that if the premises were true, then the conclusion would have to be true as well.
How do you decide whether an arguments premises are true?
A deductive argument is valid when you have the following: If all its premises were true, then its conclusion must be true, by necessity. To determine if an argument is valid or invalid (not valid): First assume that the premises are true, even if they are not; pretend that they are true.
Are the premises true?
Furthermore, the premises are actually true. (Their truth is, usually, established by some discipline other than logic.) So, that the conclusion is actually true follows by inference from the premises (and NOT because it is known independently of studying the argument).
What is an Uncogent argument?
A cogent argument is an inductive argument that is both strong and all of its premises are true. An uncogent argument is an inductive argument that is either weak or has at least one false premise.
Do all arguments have a premise?
All valid arguments have at least one false premise. An argument is a set of statements where some of the statements, called the premises, are intended to support another, called the conclusion. Logic is the study of methods for evaluating whether the premises of an argument adequately support its conclusion.
Are all unsound arguments invalid?
All unsound arguments are invalid. A sound argument must have both a valid form and true premises. Valid arguments can be unsound; but they will have false premises. Some valid arguments have true premises and a false conclusion.
What is the term for valid arguments that have true premises?
A deductive argument is an argument that is intended by the arguer to be deductively valid, that is, to provide a guarantee of the truth of the conclusion provided that the argument’s premises are true.
Which of the following could be true of a valid argument?
Valid: an argument is valid if and only if it is necessary that if all of the premises are true, then the conclusion is true; if all the premises are true, then the conclusion must be true; it is impossible that all the premises are true and the conclusion is false. Invalid: an argument that is not valid.
Can false premises lead to a true conclusion?
False premises can lead to either a true or a false conclusion even in a valid argument. In these examples, luck rather than logic led to the true conclusion.
What is an argument with false premises and a true conclusion?
So, an argument with a mixture of true and false premises is still considered to be an argument with false premises–it is false that all of the premises are true. Nevertheless, in these examples, the conclusion is true. Invalidity is a no guarantee of a true conclusion when the premises are false.
Can an argument have one premise?
A premise is a statement in an argument that provides reason or support for the conclusion. There can be one or many premises in a single argument. A conclusion is a statement in an argument that indicates of what the arguer is trying to convince the reader/listener.