Even though sociologists say that thinking is what differentiates humankind from other creatures, I'd go with Nobel Prize-winning Mexican intellectual Octavio Paz's proclamation: "Language is what makes us human. It is a recourse against the meaningless noise and silence of nature and history."
It's a great blessing and comfort to express what you think and how you feel. Some of us are more talented at it than others. Loving literature is a plus. Reading is a good habit that can double your linguistic ability and make you verbally more effective.
If you are bilingual, that's even better. You have two ways of expressing yourself. Nowadays, although speaking more than one language is a definite practical advantage in an increasingly globalizing world, scientists have begun to declare that the advantages of bilingualism are even more fundamental than being able to communicate with a wide variety of people. It's been proven that bilingualism boosts intelligence. Believe it or not, being bilingual makes you smarter. It can have a profound effect on your brain, improving your cognitive skills. Improved cognitive skills in turn protect you from the ill effects of growing old. Of course, this perception of bilingualism is very new and extremely different from the understanding of bilingualism in the 20th century and before. Many researchers, educators and policy-makers had thought that a second language interferes with cognitively speaking. Thus, a second language delays a child's intellectual and academic development for a significant period of time. However, this idea has recently been discredited.
Claudia Dreifus interviewed New York Times Canadian cognitive neuroscientist Ellen Bialystok, a distinguished research professor of psychology at York University in Toronto, after she was awarded a Killam Prize last May. Bialystok explained:
There's the executive control system in your brain. Its job is to keep you focused on what is relevant while ignoring distractions. It's what makes it possible for you to hold two different things in your mind at one time and switch between them. If you have two languages and you use them regularly, the way the brain's networks work is that every time you speak, both languages pop up and the executive control system has to sort through everything and attend to what's relevant in the moment. Therefore, the bilinguals use that system more, and it's that regular use that makes that system more efficient.
In this way, bilingualism sharpens the mind and delays the onset of Alzheimer's symptoms. Maybe that is why Federico Fellini, the world-renowned Italian film director, stated, "A different language is a different vision of life."
Years ago, I went to a Turkish fundraising event in New York for a Turkish-American candidate for Congress who had been born and raised in the U.S.. When he came to the microphone to give his speech, everybody was so excited and proud of him. Maybe he was the first Turkish candidate they had seen. However, after he said "iyi akşamlar" (good evening), in a heavy American accent, he gave his entire speech in English. After he had finished his speech, the crowd felt nothing but quiet disappointment. People didn't consider him Turkish enough! That reminded me of Nelson Mandela's words: "If you talk to a man in a language he understands, that goes to his head. If you talk to him in his language, that goes to his heart."
While he didn't win the hearts of Turkish-Americans that night, he was a great inspiration to me. When I had my children, I promised myself I would raise them to be bilingual so they would not feel like immigrants in the U.S,, while at the same time, not feel like tourists in Turkey. Our simple rule is "speak Turkish at home and English outside." However, I have to be very persistent in keeping them speaking Turkish at home, to help them retain whatever they have learned and improve their Turkish-speaking abilities day by day. Since they speak English the majority of the time, it's kind of challenging to get them to speak in Turkish, though. However, it is worth all of the effort, not only to help them foster a connection to their ancestors but also to help them strengthen and exercise their brains.
"I think, therefore I am," the father of modern philosophy, Rene Descartes, famously said. I'd say, "I speak, therefore I am," since language is the most effective tool to express ideas and thoughts. Doesn't a mind immerse itself in language? Isn't language the mother of thought? Language is the conduit through which the human mind expresses itself.