The UFOs argument

Let’s consider the following argument
All UFOs are spaceships,
All spaceships are extra-terrestrial,
Therefore, some UFOs are extra-terrestrial.

This argument appears to commit the existential fallacy. The first premise, “All UFOs are spaceships,” is a universal statement that does not imply the existence of any UFOs. The second premise, “All spaceships are extra-terrestrial,” is also a universal statement that does not imply the existence of any spaceships. However, the conclusion, “Some UFOs are extra-terrestrial,” is a particular statement that implies the existence of at least one UFO. Because the conclusion implies the existence of something that was not implied by the premises, the argument commits the existential fallacy.
To avoid committing the existential fallacy, it is important to make sure that your conclusion is properly supported by your premises, and that you are not inferring the existence of something from a premise that does not provide any information about the existence or non-existence of that thing. In this case, to avoid the fallacy, the conclusion could be revised to say “If any UFOs exist, then some of them are extra-terrestrial,” which would properly reflect the information provided by the premises.

We can make a universal statement without implying the existence of at least a member of the class to which it refers; but, when we make a statement about some then we need to now some to differentiate it from another some.
This means that universal statements do not necessarily imply the existence of any members of the class they refer to, while particular statements do imply the existence of at least one member of the class they refer to.
In order to differentiate between different particular statements, it is important to specify which members of the class are being referred to. For example, the statement “Some dogs are golden retrievers” refers to a specific subset of the class of dogs, while the statement “Some dogs are poodles” refers to a different subset of the class of dogs. Specifying which members of the class are being referenced in a particular statement helps to clarify the relationship between the classes being referred to, and it allows us to distinguish between different particular statements.
For example, consider the following two statements:
• “Some dogs are golden retrievers.”
• “Some dogs are poodles.”
Without further context or clarification, these two statements could be interpreted as being mutually exclusive, with the first statement referring to a subset of dogs that are golden retrievers, and the second statement referring to a different subset of dogs that are poodles. However, if we specify that the first statement is referring to a particular group of dogs, and the second statement is referring to a different group of dogs, it becomes clear that the two statements are not mutually exclusive and that they can both be true at the same time.
In summary, universal statements do not imply the existence of any members of the class they refer to, while particular statements do imply the existence of at least one member of the class they refer to. Specifying which members of the class are being referred to in a particular statement helps to clarify the relationship between the classes being referred to and to differentiate between different particular statements.