[Music] hello and welcome to philosophy vibe the channel where we discuss and debate different philosophical ideas today we're going to be looking at logical reasoning now logical reasoning is the way philosophers and scientists argue in order to determine a specific conclusion from a number of facts or statements right logical reasoning tends to be done by following a set of premises which will lead you to a specific conclusion for example premise 1 P equals Q premise 2 I have P so conclusion I have Q yes I see how one shapes their premises determines if their argument is sound a sound argument is one which all the premises are true and the argument is valid ie the conclusion logically follows the premises give me an example okay here's an example of a sound argument premise 1 London is in England premise 2 tom is in London so conclusion tom is in England now both the premises are true and the argument logically follows making it valid therefore the argument as a whole is sound yes I see now let's change this to show you an argument that is not sound premise 1 London is in Denmark premise 2 Holly is in London so conclusion Holly is in Denmark now this argument is not sound however it is a valid argument the conclusions logically follow the premises ie if London was in Denmark and Holly was in London then Holly would be in Denmark however the reason it is not sound is because the premises are not true because as we know London is not in Denmark yes I understand now I will show you an argument that is not sound but not because the premises are not true the premises will be true but the argument will not be valid the conclusion will not follow the premises consider this Promised One fred is human premise two humans are in London so conclusion fred is in London what can you see wrong with this well here we can see the premises are in fact true Fred is a human and there are humans in London even though the conclusion is true because for it is in London the argument is still not sound because it is not valid the conclusion did not follow the premises just because some humans are in London does not mean all humans are in London and therefore does not mean fred has to be in London exactly just because Fred is a human does not mean he must be in London as there are billions of humans all round the world so even though the premises and the conclusion is true the argument is still not sound very interesting moving on there are three main types of logical reasoning which we're going to run through the first one we will look at is deductive reasoning are you familiar with this yes deductive reasoning or a deductive argument is an argument that is intended to be completely true and certain that is if the premises are true your reasoning will lead you to a logically certain conclusion correct so to give an example of deductive reasoning premise one all men are mortal premise two I am a man conclusion I am mortal or another one premise one all humans have brains premise two I am human so conclusion I have a brain yes in each of these if the premises are true the conclusion is certain exactly now then this differs from the next method of logical reasoning and that is inductive reasoning with inductive reasoning the arguments conclusion is highly probable if the premises are true so instead of being absolutely certain like deductive reasoning with inductive reasoning the argument is meant to establish a high probability of the conclusion so with the evidence we have it would seem highly unlikely that the conclusion would be false right so can you give us an example of this premise one for the past ten years every time I walked past the neighbor's dog it has not bitten me premise 2 I will be walking past the neighbor's dog today so conclusion the neighbor's dog will not be biting me today I see or another example would be premise 1 all known living organisms need water to survive premise 2 every time we have found a new living organism it needs water to survive so conclusion if we found a new living organism it would need water to survive so as we can see in the last two examples the conclusions are highly probable but they are not logically certain so this would be an inductive argument right so what is the third method of logical reasoning the third method is known as abductive reasoning this is similar to inductive reasoning in the sense that it does not lead to a logically certain conclusion however with abductive reasoning the conclusion is even less probable than inductive reasoning in fact with abductive reasoning you are making an inference it's almost as though you are guessing based on the evidence you have in the observations you have made you create a theory where the simplest the most likely conclusion will follow okay could you give an example of this okay premise 1 fred has been stabbed premise 2 a knife matching the stab wound has been found with Tom's fingerprints on their conclusion tom stabbed fred rice although not certain but based on the observations we have found is the most likely conclusion unlike inductive reasoning the conclusions are not highly probable yes it does seem like tom stabbed fred based on the evidence but then again there could be a hundred different reasons why Tom's fingerprints are on the knife that does not necessarily mean he stabbed Fred yes I understand abductive knowledge is very common amongst scientists who come up with theories and hypotheses based on the evidence they have and what they can observe very true well that's all the time we have for now thank you for watching we hope you enjoyed the vibe and we hope this video helps you formulate your own logically sound arguments don't forget to like share and subscribe and help us grow this channel take care until next time