Artificial life, or Alife, is a field of study which examines systems that relate to life, its processes, and its potential evolution through the use of computer models, robotics, and/or biochemistry. As such, there are three distinct approaches towards Alife: 'soft' linked to software; 'hard' linked to hardware; and 'wet' linked to biochemistry plus the option to use all three together.
"Artificial Life is the study of man-made systems that exhibit the behaviour characteristics of natural living systems. It complements the traditional biological sciences concerned with the analysis of living organisms by attempting to synthesize life-like behaviours within computers and other artificial media. By extending the empirical foundation upon which biology is based beyond the carbon-chain life that has evolved on Earth, Artificial Life can contribute to theoretical biology by locating life-as-we-know-it within the larger picture of life-as-it-could-be." Chris Langton
Today, the definition of life has not been expanded to encompass any of the current Alife simulations, soft, hard or wet, as an 'artificial living system'. There are some fairly obvious emotive reasons why this might be the case, but a more rational argument is based on the fact that Alife, at present, is not part of any recognised evolutionary process within our local ecosystem. Of course, the discovery of some truly extraterrestrial life form, even bacteria, might open up the debate as to what constitutes a 'living system'. However, there are different schools of thought concerning Alife, which we might initially characterise as follows:
- Weak Alife: a system that just simulates life
- Strong Alife: a system that fulfils the criteria of life
Of course, there is still the issue of who defines the 'criteria of life'; but we shall start with an initial criteria that was forwarded to differentiate living cells from non-living matter:
Life possesses self-determined action within a self-organised, non-equilibrium system, which can reproduce itself.
Based on this criteria, it is possible that biology may have already created primitive 'wet' Alife in a Petri dish somewhere in the world. However, the focus of much of the Alife debate is now focused towards intelligent Alife, which typically runs in parallel with the subject of Artificial Intelligence (AI). To some, the term Artificial Intelligence (AI) may simply imply the development of a more intelligent machine, i.e. an advance computer, which when packaged into a robotic shell can carry out menial or repetitive tasks on behalf of humanity. However, any discussion of artificial intelligence can quickly expand to include the issue of self-awareness and sentience. So, at this point, the nature of the discussion can quickly change from one about the technical arguments for and against smarter machines to the more profound issue of creating artificial life. However, before delving too deeply into the issues associated with the potential evolution of AI, which is actually the topic of another section, let's try to establish some frame of reference in which this discussion can proceed.
Without necessarily trying to be too exact, what is generally inferred by intelligence and sentience and what implications might these definitions have on AI?
- Intelligence relates to the ability to learn, understand and solve problems. However, this explanation of intelligence does not explain by what methods anything is understood.
So the next question is whether intelligence can simply be driven by logical rules and algorithms or is some other form of fundamental understanding required?
- In contrast, sentience is often seen to be more ephemeral and linked to metaphysical concepts such as consciousness, self-awareness and emotions. In this context, the term sentience is being used as a catchall expression that includes all metaphysical states of the mind. Whether sentience can exist independent of any intelligence is doubtful, but clearly some life forms, e.g. animals, appear to possess some degree of sentience, while only having limited intelligence.
So what is the relationship between intelligence and sentience, which appears to be of such central importance?
Note: We might speculate that an artificial system might 'emulate' sentience by having a simplistic definition of 'self' being that which it seeks to protect. So unlike Asimov's 3 laws of robotics, this system might have what would appear to be an independent 'survival' instinct.
The diagram above attempts to make an initial clarification of the seemingly elusive relationship between both intelligence and sentience. While intelligence appears to allude to an ability to learn, understand and solve problems; it does not necessarily infer any ability to feel emotions. On the other hand, while sentience can be used to only infer emotional and perceptual understanding plus some level of self-awareness, it is unlikely that full self-awareness could exist independently of intelligence.
Why did evolution come up with both intelligence
Can intelligence and sentience be explained in terms of physical processes?
What justification is there for AI, let alone Alife?
When discussing AI or Alife, it quickly becomes apparent that many questions concerned with intelligence and sentience are equally applicable to ourselves. It would seem that the goal of AI might never be realised without first coming to understand some of the fundamental facets of our own humanity. It is for this reason the discussion about AI begins with an overview of 'human intelligence' followed by the idea of an 'emotional intelligence' before then discussing the developments towards intelligent artificial life.