The answer to this question is more complicated than just a yes or no answer. Firstly you have to define what an authentic life is and secondly what the definition of modern society is.
An authentic life is living a life true to yourself. A life filled with love, peace and joy. A life in which you feel free to be yourself, without the fear of judgment by others. To live and authentic life is the freedom to follow your heart and to live the life that will make you happy.
But to live that life, you firstly need to connect with your inner self. Most people don't take the time or have the time to discover themselves. It's only when you truly know yourself, that will enable you to realize what it is that really makes you happy and at peace. Unfortunately discovering our true selves is not that easy due to the conditioning and influence of modern society. Many people believe that if they had a lot of money, that they'll be happy, because they blame their unhappiness on the lack of money. But nothing can be further from the truth - money can't buy you happiness.
One's happiness is determined by how closely we live to our authentic self. For example if you're an accountant, but your passion is to work at a wildlife sanctuary, you'll be unhappy, even if you earn a good salary. So the secret is to discover your passion and to live it. When you're doing something that fills your heart and soul with happiness, then love and peace will also become part of your life and you'll be moving closer to living your authentic life.
I said "your authentic life", because every one of us has a different passion and purpose. So it's impossible to define an authentic life, because each one of us will find happiness in a different place. But the common denominator is that each one of us will be living an authentic life and by doing so, we'll connect with people on a deeper level because we are at peace with our lives. There is no competition, no envy, just love for each other.
To define modern society is much easier, it is all about money, power and ego. Your self-worth is measured in
materialistic possessions and not by your happiness. You
are conditioned by modern society's laws and regulations and have no freedom to be yourself. Your whole being and thinking revolves around the expectations of society and these expectations force you to live a life so far from your authentic self, that you forget who you really are, making you loose that connection with your inner self.
In short an authentic life is a living a life that makes you happy because you're following your passion and not the money.
Modern society on the other hand is all about money and materialistic possessions.
This brings us back to the question: "Can you live an authentic life in modern society?" My view is no, you can't.
Even if you live your passion and what ever you're doing is exactly in accordance with your authentic self, you still need to make money to survive in modern society and money is the barometer of modern society. Eventually you'll succumb to temptation or need of money, even if your doing exactly what your suppose to do, you'll try to figure out a way to make more money with what ever you're doing. So money becomes your deciding factor again and not happiness. And when you're neglecting your happiness for money, you are moving away from your authentic self.
So my view is that you can live an authentic life in modern society, but it will be short lived before you succumb to
modern society's expectations and influence. So to live and everlasting authentic life, we'll need to remove ourselves
from modern society and live a simple life, where we'll have time to see to other's needs and not just our own self