In 2016, Artificial Intelligence (AI) celebrated its 60th anniversary of the Dartmouth Workshop, which marked the beginning of AI being recognised as an academic discipline. One year on, the pace of AI has captured the wildest imagination of both the scientific community and the general public. The term AI now encompasses the whole conceptualisation of a machine that is intelligent in terms of both operational and social consequences. With the prediction of the AI market to reach 3 trillion by 2024, both industry and government funding bodies are investing heavily in AI and robotics. As the availability of information around us grows, humans will rely more and more on AI systems to live, to work, and to entertain. Given increased accuracy and sophistication of AI systems, they will be used in an increasingly diverse range of sectors including finance, pharmaceuticals, energy, manufacturing, education, transport and public services. It has been predicted that the next stage of AI is the era of augmented intelligence. Ubiquitous sensing systems and wearable technologies are driving towards intelligent embedded systems that will form a natural extension of human beings and our physical abilities. Will AI trigger a transformation leading to superintelligence that would surpass all human intelligence? This white paper explains the origin of AI, its evolution in the last 60 years, as well as related subfields including machine learning, computer vision and the rise of deep learning. It provides a rational view of the different seasons of AI and how to learn from these ‘boom-and-bust’ cycles to ensure the current progresses are sustainable and here to stay. Along with the unprecedented enthusiasm of AI, there are also fears about the impact of the technology on our society. A clear strategy is required to consider the associated ethical and legal challenges to ensure that society as a whole will benefit from the evolution of AI and its potential negative impact is mitigated from early on. To this end, the paper outlines the ethical and legal issues of AI, which encompass privacy, jobs, legal responsibility, civil rights, and wrongful use of AI for military purposes. The paper concludes by providing a set of recommendations to the research community, industry, government agencies and policy makers. To sustain the current progress of AI, it is important to understand what is science fiction and what is practical reality. A rational and harmonic interaction is required between application specific projects and visionary research ideas. Neither the unrealistic enthusiasm nor the unjustified fears of AI should hinder its progress. They should be used to motivate the development of a systematic framework on which the future of AI will flourish. With sustained funding and responsible investment, AI is set to transform the future of our society - our life, our living environment and our economy.