How do we know that other earthly creatures are not capable of higher thought?

Question

If we are not that creature.

Answer 1

That's a tricky question, but I would approach it like this:

Higher thought refers to creative and cognitive capacity, for the most part. In other words, it marks a shift away from basic instinctual behaviour. Some creatures can, operating under certain conditions, learn to be creative (or at least to mimic) - think of dogs learning to use doorknobs. I'm not convinced, however, that animals ever consider what is beyond their immediate environment. I highly doubt when an animal gets hungry, it sits down and ponders why that is. We do. Some greater apes do in a more rudimentary fashion.

I think the more determining factor is an issue of physiology. Our wonderful hand design (opposable thumbs) allows us to explore things through construction and destruction. If we weren't able to do it, we simply wouldn't think the way we do and over millenia our neural patters have been shaped by that ability to innovate and explore.

I'm no brain expert, but I'm fairly certain we can know how much other animals know by comparing our brains. Higher order functions take place in a particular part of the brain, and other animals undoubtedly are less developed in those areas than we are.

Answer 2

It is not an endless cycle of birth and rebirth. It is meant to end after the human form, which is considered to be most evolved of species. Why? Because in the human form of life, one can question. Who am I? Where have I come from? What is the purpose of life? The lower species do not have that ability.

If not, even as a human being, if one dies, then according to one's activities, karma, the soul would have to take another birth. It is not necessarily another human birth. If one's actions were very abominable, if one's consciousness was very degraded, then the desires one is left with at the time of death may force one to take a lower birth again in a lower species of life. This is called transmigration.

http://www.atlantaharekrishnas.org/newsgroup/kcprinciples/0093.htm

According to the Hindu tradition, 'a jiva (from the stage of a protozoan, perhaps) attains competence for a human body after undergoing 8,400,000 births (in lower forms of life).
Brihad Vishnu Purana gives the details.

http://www.vedanta-newyork.org/articles/concept_of_evolution.htm

The Hindu Upanishads say that humans are the
highest of all creation. The virtue gained through
taking thousands of lower births gives the
eligibility for a soul to take human birth.

Answer 3

" higher thought" must be more defined for a meaningful answer. Question too broad.