"What is the most resilient parasite? Bacteria? A virus? An intestinal worm? An idea. Resilient, highly contagious. Once an idea has taken hold of the brain it's almost impossible to eradicate. An idea that is fully formed, fully understood..." ~ Dom Cobb (Inception)
Aren't we all embodiments of ideas that take root in our minds? Meeting any person is being in presence of thoughts, that have taken grip of him, at that moment. We don't deal with people but, ideas, archetypes of thoughts, tendencies and philosophies that inhabit their minds. A personality is the representation of a philosophy, a sum total of tendencies, that is made apparent through a person's words, behavior and actions. What makes us, is a magnificent network of interconnected ideas, that we call the core culture of our being - the philosophy of life, ingrained in our brains.

We humans are unique amongst animals, in our ability to pass on knowledge, culture and seeds of thoughts to future generations. Through us, the ideas of our forefathers live on, and in us lie the progenitor ideas that will guide our progeny. In that sense, ideas never die, they only keep getting mimicked, inherited and modified, sometimes leading to the synthesis of more powerful ideas.

Thoughts are things, and they infect minds like no other parasite on Earth. These pieces of information, ideas, thoughts or culture capsules, that are copied, transmitted and modified by every human mind are known as 'Memes'.
A Tale of Two Replicators
We arose from the first progenitor molecules that inhabited the primeval organic soup of the young Earth, who had the ability to replicate themselves. From what was pure chemical reactions, arose intent, a will to survive and procreate. Through a process of recombination, variation and natural selection, these primeval strands of life, gave rise to DNA, the chemical code that forms the book of life and creates the wide variety of organic life forms that flourish on Earth. Organic life was made possible by these first replicators, now known as genes, that determine every one of our physical traits. They grant man with, amongst other gifts, the most beautifully complex clump of matter in the universe - the human brain.

For millions of years, beings were at the mercy of genes, the audacious pieces of organic algorithms, which programmed and dictated their behavior, until they gave rise to the highly developed human brain, which projects the mind, a highly 'self-aware' entity, capable of free will, independent thought, reflection, memory, learning and most importantly, the ability to mimic behavior, empathize and communicate through language and script. Matter evolved to a point where it could question itself.

This inadvertently set the stage for evolution of second generation of replicators, (now known as) memes - ideas or cultural seeds, behavior, any manifestation of thought, transmitted non-biologically, from one mind to other, directly or indirectly. Memes or ideas control minds and the actions driven by minds change the world, thus establishing memes as potent forces of creation. The word was coined and the idea of a meme was put forth by Richard Dawkins in his legendary book, The Selfish Gene, published in 1976.

Minds are abodes of memes, where they thrive, grow and prepare themselves for plunging into fertile minds, ripe for intellectual infestation. This article is a meme, rapidly hacking through your brain as you think about what it says.
The Algorithm of Darwinian Evolution - Applied to Ideas
Darwin's idea of evolution is not restricted to organic life. In fact, it is just one small sub-set of what is now known to be Universal Darwinism. Evolution, based on Darwinian principles is not a specific process, but an algorithm, based on variation, selection and heredity. In case of organic life, it selects the best organisms, with the most conducive genetic constitutions, that are able to survive and adapt to the environment. This algorithm can be applied to any set of entities capable of variation and heredity, subjected to selective forces.
Evolving Memes
Now imagine this algorithm being applied to 'ideas', 'thoughts' or any piece of 'culture' or information that can be replicated and transmitted. Every idea is seeded in your mind, from other minds and external media, so it has the property of heredity.

Ideas or memes can be modified, changed and enhanced by the mind receiving it and evolve into more superior forms or degrade - which grants them with the second important property - variation.

Thirdly, only those ideas survive, that find followers and are potent enough to find a permanent place in the minds of people, as the culture of an era. That qualifies them for the third condition, which is selectivity. Ideas compete in the thought space to gain an edge over each other. The ideas or memes that win, rule the world.
Evolving memes compete against each other by influencing the actions of individuals, whose minds they inhabit. So, when you see two people fighting, in actuality, it is the memes that are struggling against each other. What you see, are people, but the causal forces in conflict are memes. People die, yet ideas live on. That's what sets humans apart from other animals - culture. It is the sum total of meme clusters inherited by a generation. Ergo, memes are the second generation of replicators, who control the world now, and will largely influence the course of future evolution.
Memes and Free Will
Memes cannot undermine the importance of free will - our ability to make choices that are conducive to our well-being. However, the conformist forces that rule the world tend to override independent thinking at times, imposing their will upon the world. A child learns through imitation and he continues to do so while growing up. Most ideas that form the core of our being, are accepted unquestionably through imitation. There are memes that are adopted by choice and some that are assimilated unquestionably by default.
Examples of Powerful Memes
The empires of the future will be empires of the mind.~ Winston Churchill
Every piece of information (graphic, textual, behavioral or any other form), representing tangible and non-tangible entities, transmitted through any medium to spread through imitation, is a meme. The idea of a meme is thus all-encompassing. Here are some of the most influential memes that have shaped human civilization.
The idea of an all-controlling anthropomorphic 'God' entity is one of the most powerful memes that has been passed over generations. It dominates the world view of most minds, and has an origin in deep-rooted fear and ignorance about the way the world works. This meme has been responsible for much bloodshed and wars for mankind over the centuries, while also serving to be an effective defensive mechanism, shielding humans from the impersonal nature of the universe. The fear and reverence induced by a Godhead, has served to provide a code of ethics and a support mechanism for humans, adding meaning and granting a sense of purpose to many lives. The idea of a God has evolved over time from the primeval anthropomorphic punishing entity to the modern perception of God among a few, as the laws of the universe themselves, that weave the beautiful tapestry of this world.
A meme that's deep-rooted in our collective vision of the world is the concept of an undying soul, promising afterlife. The meme may have arisen out of an inability to accept death, as a phenomenon. The fact that a person ceases to be anything, after physical death is too unnerving to accept. The idea of a soul provides continuity. Though, till date, there is no conclusive scientific evidence proving the existence of a soul, it continues to be a powerful idea, that protects some from the idea of impermanence and nihilism. For many, it is the support system that helps us cope with the idea of our mortality.
To have 'more' and aim for material abundance is the central thought that fuels modern cultures. This meme of consumerism is the most dominant force that pervades societies today, contributing to a new kind of slavery and severe depletion of natural resources. It is only a small part of the larger meme set, which is the modern capitalist system, that has 'consumption' to be the core driving force. 'Money' as the sole measurement of value, is another idea, which is a part of this meme cluster. With an increasingly representational world of man-made objects and environment substituting the nature-oriented life of old, consumerism thrives to provide material pleasures, in an increasingly desensitized world.
Romantic Love
The much sought after ideal of romantic love is another meme that has been around since ever. The idea of a soulmate and the promise of a happily ever after drives humans to go about their lives in search of the one. Movies and literature have played a large role in spreading this meme. Much despair, disillusionment and depression follows for some and some lucky ones do supposedly find it. This meme contributes to much irrational behavior in humans, while also driving many industries built around this singular human passion of finding the one. This meme is strongly supported by the biological mating drive, which is powered by a potent cocktail of neurotransmitters and hormones, programmed by primordial genes. The idea of true love, is much wider and all-encompassing, of which, romantic love is only a singular aspect.
In the sciences, a central meme that forms the substratum of thought is reductionism - the idea that knowledge of the parts, equals the knowledge of the whole. It drives ambitious projects like the building of large particle smashers, that reveal the fundamental elements which build matter. It has led to the myopic view that knowledge of the fundamental particles and their interactions, will provide us with a Theory of Everything. In my opinion, this is taking things a bit too far, when so many problems on a macroscopic scale, like turbulence remain unsolved and inaccessible.
Every culture has its set of archetypes and role models, which are emulated by entire generations. These male and female archetype memes shape the ideas of the Ideal or Successful man or woman. For example, the male archetype in prehistoric times may have been the brave and powerful warrior or hunter, while in modern times it is the nerd, in control of vast technology corporations. These archetype memes vary from culture to culture and they are shaped by the idea of success.

The next level in the evolution of memes would be their transcendence of the organic substrate they currently dependent upon. Artificial intelligence - a self-aware entity, capable of independent thought, would be the crowning glory of memes, the second replicators. A mind free from organic constraints, endowed with the power of the imaginative human mind and the brute computing power of a machine would surpass all known limits of cognition and technology.
Mind as a Meme Complex
The mind is everything. What you think you become. ~ Buddha
Modern neuroscience has effectively established the brain as the projecting mechanism of the mind, effectively outmoding mind-body duality, as a theory. It has been firmly established that all our cognitive abilities arise from global activity of locally connected neurons. Every piece of information or meme, that the brain receives, is represented or remembered through connections between neurons. Effectively, your personality is the sum total of acquired habits which result from the memes accumulated over your lifetime. Every mind is a unique meme complex with its own potpourri of thoughts.

The quality of our lives is largely a function of what memes we let reside in our brains, forging our belief systems. Ergo, changing ourselves requires a fair bit of introspection. With an unbiased inner eye, we need to be aware of the meme algorithms that run in our minds leading to a disturbance of peace, stunting our growth in the process - memes that limit our potential as sentient beings. Many outdated meme algorithms, once accepted by default need to be re-examined and 'uninstalled' if need be, to make way for better thoughts and ideas, which would ultimately lead to a better life.
The mind, as a software, needs upgrades and it's a constant process of reinventing ourselves to meet the ever-changing challenges of life. While nobody has the perfect key to happiness, the reason for unhappiness in most lives is stagnation, the result of adherence to an outdated meme cluster, badly in need of replacement. The key lies is introspection - the reflective quality of a mind. With heightened self-awareness, we can choose what we want, instead of being automatons and slaves to randomly injected memes that control us. For only then, can we freely choose our path.