A Sentient Alien Species, if they exist, will likely look humanoid

Now, I shall begin. CASE FOR HUMANOID FEATURES IN SENTIENT EXTRATERRESTRIAL LIFE By C. E. Turner. Whether you believe in the "Christian God" and a Young Earth divinely created or in no God and an Old Earth shaped by factors like Natural Selection, it's reasonable to assume that through either process life forms with the best features would form. After all, an Intelligent Designer would create His physical creations with a highly functional design. Doubtless His sentient creations would display the greatest amount of design. If you believe that life is shaped by the process of Evolution through mutations and Natural Selection, it's also presumable that a sentient life form would also possess the physiological means needed to take advantage of this sentience. In either case, I would argue that the body structure that goes best with sentience is a humanoid body. 1. Bipedalism For shaping, holding, and ultimately using tools requires a structure which is handlike (that is, fingers with opposable thumbs). You cannot hold a tool with hooves or wings. A claw would have a quite difficult time manipulating an object held within its clutches. My opponent may make the argument for multiple tentacles which can each serve the role of a finger, but wouldn't an arm with a fingered hand at the end be more efficient? At the same time, two arms with touch-sensitive hands do not fare well holding up a person, as this would require almost constantly having your hands walk across the tough floor. That may mess up your fingers and make them less dexterous. Also, can you handle a tool when your hands are busy pushing against the ground to support your weight? The best design, clearly, is to have your hands off the floor. To have your arms and hands off the floor, you'd obviously need legs that can support your weight without support from your hands, meaning that either you need more legs or you need stronger legs. If you have more legs and arms (like a mythical centaur does), you'd be more likely to trip over your legs. Also, it'd require a long horselike back structure. If you fell on your back, you'd find it very difficult to stand, as your arms would have a hard time lifting such a heavy part of your body into a proper position. That is, a sheep with arms would still have a difficult time getting up if it fell on its back. Also, it'd be harder to turn around or look behind you, and your ability to jump would be impaired by your weight. Two strong legs (as humans have) make for easy turning around, sitting down and getting up, and jumping. Therefore, I think that I have proven that two arms and two legs is a useful system compared to other physiological systems. 2. Body Symmetry Humans possess Bilateral Symmetry, making them part of a group called "Bilateria". I do not know the consensus of the scientific community on why Bilateral Symmetry exists, if such a consensus even exists. But, as a large percentage of known life forms are Bilatera, there's probably a very good reason for it. And. .. here's an article which may explain it. . http://m.sciencemag.org... So, methinks it is likely that a sentient lifeform will have a Bilateral Symmetry, as humans do. 3. Head A humanoid life form would need a head. In the case of a life form is Bilateral and Bipedal with two arms, the head would need to be put in a good place. Where it is in humans, with rotation of the head possible and no other body parts to impede the head's ability to see, the human position for the head is the best place for a head that contains eyes. Now, the ability to see what is around you is essential for the survival of a large organism, and it is also vital for establishing a civilization. I am sorry if this offends blind people, but society could not function if everyone was blind. The location of the head makes it the ideal place to put eyes. The head is also an ideal place for the brain, as otherwise the head would be empty. Also, signals from the eyes to the brain can travel at maximum speed if the two parts are right next to each other. The ability to speak intelligently also works best when the mouth is right next to the brain, as does the ability to smell and hear. I await my opponent's rebuttals.