Prior to the written word, we had to devote time and effort to passing down information through the spoken word. By offloading this task to an external device (wall, tablet, parchment, paper, book, screen), we've been able to use that time and brainpower to focus on other items, while also increasing the fidelity of our history and what we can learn from it. People lament the loss of an oral storytelling culture. It is a loss, but we've gained as well, so mathematics, literature, philosophy. We are able to build on the past in a way we weren't before.
Prior to the plow and domesticated animals to pull them, we used to have to plant manually or practice a more hunter & gatherer lifestyle. By offloading these tasks we are able to secure our future needs, and live a life less of subsistence, and more of security in our health and future. Some people lament the loss of connection to the land, the feeling of oneness with the seasons. It is a loss, but again, we've gained as well. This free time has allowed us to study what we've written, and build upon the past.
You could make a case that using these tools (and hundreds more in our history) takes the humanity out of you, and relies on the tool for it. I would make the case that using these tools is what makes you human, as without them, what's really the distinguishing feature that separates you from the apes? To me, nothing defines humanity more than the constant improvement of our race, our reach, and our capabilities.
That I carry around a small computer in my pocket that connects to a much larger network and allows me near instantaneous connection to my family, friends, coworkers, and the largest accumulation of knowledge the human race has ever seen might seem like I'm trading away what you think makes us human, but since I use this to keep in touch with friends, be more mindful of important things to them, learn about what I'm doing to be more safe, secure and healthy, and share with myriad sub-cultures, I strongly disagree.