A "conscious" or "thinking" machine should behave erratically, in a sometimes stupid and sometimes smart way. Human "intelligent" behavior is about unpredictable oscillations between emotions and reason; this is what Homo Sensus Sapiens is about. Paradoxical as it sounds, we call "intelligent" to a species characterized for being equally and randomly stupid and smart.
In first person, we know we are conscious although there is not a definitive way for proving it. In third person, it is also impossible to verify that someone or something is conscious. All we do is to perceive signals—sounds and images—infer consciousness and attribute it.
Any software or robot can pronounce the words "I am intelligent" or "I am conscious," but those are not proofs of intelligence. In practical terms, consciousness and intelligence are perceived and attributed. This attribution depends on our empathy and criteria for anthropomorphizing.
We tend to infer that others are conscious because they behave, look or, in Turing terms, answer questions like us. The Turing test is therefore a social experiment about perceiving and assigning intelligence to a machine, not about proving that the machine thinks. This is a social game we play everyday.
A "thinking machine" is actually a social machine, not a functional but isolated mind.
The idea of creating a singular intelligent machine that will solve the mysteries of reality through flawless logic and will spring a whole new species is now a domain of science fiction. That singularity idea is not an event horizon but an endless effort.
The human mind is resilient because decentralized networks of other minds and knowledge sustain it. As we grow we enter those networks through language and concepts that don't obey to perfect logic, we then become resilient minds by navigating and exploring those networks, and finally we leave them as we lose brain capacities, for instance with Alzheimer's. This is an analogous process: we are never absolutely inside or outside the networks of human knowledge.
In this process, the words and concepts are characterized by ambiguity. Logic and perfection are only present in artificial languages—mathematic, geometry and software—that we cannot use to communicate in the everyday life.
Imperfection and ambiguity define human thinking, and that's why even in science fiction humans usually find unexpected paths across the logic of the machines to beat them.
Therefore, the possibility of a flawless super-intelligent machine seems like a matter of science fiction: We can never condensate the entire knowledge of the world, so we cannot teach a machine how to do it. We can teach a machine how to acquire knowledge, but it will always be an unfinished process.
This doesn't mean that Artificial Intelligence is irrelevant.
We don't fully understand brains and minds yet, and that makes Artificial Intelligence and "thinking machines" more relevant now than ever.
We can solve practical problems simulating specific elements of the mind through machine and deep learning. This is what artificial experts systems around us currently do. But it doesn't mean that we are creating actual minds: simulating minds is like creating artificial meat that vegans can eat, reorganizing chemical compounds found in plants. The simulated meat tastes like meat but is not.
Or we can try to create real meat, not to imitate it, for instance by cloning cow cells. Maybe the cloned meat and the replicated mind won't alter society because we already have the original ones, but they will take us to a whole new level of understanding.
In the end, the efforts for understanding—simulating or creating— minds will be relevant if they improve coexistence. We are well aware about how religion, exacerbated ambition and intolerance lead us to social tragedies, because we don't know how to balance the delicate equilibrium between emotions and reasons.
As we approach a verge between pacification and barbarity in various regions of the world, Artificial Intelligence allows us to integrate all we know and all we need to know for achieving coexistence and balance among the current organic machines that we are and, maybe, the inorganic machines that will come.