The Time Traveller is a brilliant human being. He has to be in order to imagine how to build a working time machine. This makes him two things. He is a good enough scientist to work out how to make it work, and he's a good enough inventor to actually build it.
The first paragraph of the story further cements into the mind of a reader that the Time Traveller is a good inventor. The men are sitting in chairs that were invented by the protagonist. Chapter 2 also tells readers that the protagonist was "too clever." This first means that he is indeed smart; however, the problem is that he is so clever as to not be believed. That's a slight character flaw, but it does show readers that the man's mind is working at a level above everybody else's mind. The Time Traveller is constantly pursuing science and furthering his knowledge. In my opinion, this makes him a sympathetic and likable character. He pursues science for the sake of the pursuit and finding answers. He's willing to take risks on a hypothesis, and he's willing to adjust it.
Unfortunately, despite his massive amounts of intellect, he isn't necessarily able to see the meaning of his discoveries. For example, he thinks that maybe the Eloi are descended from the idle rich of his time period or time periods after that, yet he isn't entirely willing to accept that he is a part of that social class in his time period. We are introduced to him lazily sitting in comfy chairs talking with other men doing the same thing while the servants are presumably seeing to the real work of the house.
And he put it to us in this way—marking the points with a lean forefinger—as we sat and lazily admired his earnestness over this new paradox (as we thought it) and his fecundity.